G.ho.st, which stands for “Global Hosted Operating System,” is claiming it has a pending trademark registration for the tagline “no walls.”

G.ho.st has used the phrase for almost 18 months and is alleging that it pertains specifically to operating systems (as shown in the screenshot here).

In a letter sent earlier this week to Microsoft CEO Steve Ballmer and many others, which BoomTown has obtained, G.ho.st CEO Zvi Schreiber claims that the software giant has violated G.ho.st’s pending trademark for the ad phrase “no walls” and asks Microsoft (MSFT) to remove it from the company’s marketing materials.

Microsoft’s advertising campaign, which launched this month and had a rocky start with poorly received commercials featuring comedian Jerry Seinfeld and Microsoft Founder Bill Gates, uses the taglines “Imagine No Walls” and “Life Without Walls” to tout its Vista operating system. (See a screenshot of one example below; click on it to make it larger.)

G.ho.st, which is hosted by Amazon (AMZN), is yet another of many attempts to make cloud computing real and is competing to grab customers from the software-based Windows powerhouse.

A Microsoft spokesman, in an email to me, dismissed G.ho.st’s claims.

He said:

“We are aware of their concerns and believe their claims have no merit. We are not aware that Ghost has any trademark registrations or other rights that would be infringed by our ‘Life Without Walls’ campaign. To our knowledge, the right they have asserted, namely, a U.S. ‘registered trademark application,’ in the phrase ‘No Walls,’ does not exist.

“To our knowledge, Ghost has no trademark registrations or other rights in the phrase ‘No Walls.’ Even if they did, they cannot prevent others from using the words ‘no walls’ together in a sentence or in a descriptive manner in ad copy. Nor can they claim ownership in word ‘wall’ or the idea of a wall. The tagline for Microsoft’s new ad campaign is ‘Life Without Walls’–a slogan that, taken in its entirety, is not confusingly similar to Ghost’s purported ‘motto.’”

G.ho.st launched at our D: All Things Digital conference this past May (where Ballmer and Gates also appeared).

Here are two videos showing the start-up’s whole demo:

And here’s G.ho.st CEO Zvi Schreiber’s full email letter to Ballmer (with email addresses and other personal information redacted):

From: “Zvi Schreiber (G.ho.st)”
To: [Steve Ballmer]
Cc: [redacted]
Sent: Wednesday, September 24, 2008 12:15:41 AM (GMT+0200) Auto-Detected
Subject: G.ho.st Virtual Computer NO WALLS trademark

[4] E.g. http://www.microsoft.com/windows/
http://www.microsoft.com/windows/possibilities/products/default.aspx?vindex=2
http://www.microsoft.com/windows/possibilities/default.aspx?ocid=ftp

But–as many readers have requested–they will all be available in their entirety in this column.

In the less contentious spirit of DEMOfall and TechCrunch50, two demo conferences taking place simultaneously this week, we’re happy to bring you all the demos we had onstage at D6.

Last, but not least: the G.ho.st Web operating system, which lets users access their desktops from any computer with an Internet connection and is also a joint technology venture between Israelis and Palestinians.

The video of the G.ho.st demo is in two parts.

In part one, CEO Zvi Schreiber shows off the “Global Hosted Operating System,” which is hosted by Amazon, yet another if the many attempts to make cloud computing real.

In part two, Zvi goes over the various features and applications of the G.ho.st product and discusses the business plan and how the Israeli-Palestinian collaboration works.

“Where’s Jerry here? He is like a ghost,” said a Yahoo (YHOO) exec to me last week.

The exec was referring to the plans for a major overhaul of the management structure of the troubled Internet company–the dreaded and inevitable reorg that BoomTown wrote about in detail last week that is expected to be announced this week.

Many execs have told BoomTown that Yahoo CEO Jerry Yang has been strangely absent from the communications around the reorg, which has been driven largely by President Sue Decker.

Well, ghosts aren’t real, but fear and uncertainty clearly are at Yahoo these days.

Thus, as Yahoo gears up for its annual meeting on Aug. 1, where it faces a proxy battle with billionaire Carl Icahn (whose billowing sails have been much trimmed by the huge drop in Yahoo’s stock price recently), here’s a certainty: Yet another bumpy week for Yahoo, its employees and shareholders.

Last week, BoomTown outlined the changes that Yahoo is likely to announce this week, part of a massive management overhaul that has spurred the departures of top execs and focused much attention on how Yahoo is going to be organized by its leadership for its many challenges going forward.

That is, of course, if that leadership does go forward.

This is not to say that either Yang or Decker is under any particular pressure to go, despite all the turmoil with the Internet giant and also from external forces.

In fact, I think Decker will soon get the CEO job outright.

As I wrote in my post last week of other possible CEO alternatives for Yahoo (and I stand by my pick of Mark Cuban, my friends!):

It’s the obvious question, of course, to ask whether the co-founder of Yahoo has what it takes to manage the company through what will doubtlessly be a very difficult year. … As Yahoo continues to be in limbo, pressure is sure to mount heavily on Yang, and it is not a stretch to imagine he will not remain in the top job at the troubled company for the long term.”

It is even easier to imagine after the last week, which saw much upheaval in the exec ranks, with several top managers headed out the door and others clearly considering scaling the perimeter fence.

There’s lots of reasons for that, including the form of the expected reorg that might put power–besides with Yang and Decker–into the hands of two key execs: Hilary Schneider and Ash Patel (both pictured here).

Patel, the longtime Yahoo exec who is currently EVP of its Platforms and Infrastructure division, is expected to lead a new Global Products group–made up of “global” properties and products.

Much of the Network division, which until recently was under the leadership of the now departed Jeff Weiner, will move under Patel, including search, mail, instant messenger, front page, platforms and social networking.

And Global Partner Solutions EVP Hilary Schneider is apparently to be placed over the entire U.S. region. Schneider keeps all of ad sales, but gets the Yahoo Media Group (which was also in the Network division).

That shift will bring together Yahoo’s vast content properties, like Yahoo Finance, with ad sales and align them more closely.

How closely Decker will hew to this setup, which was proposed internally over the last two weeks with little input from most managers, will be interesting to see.

Obviously, plans could change given the tepid reaction internally to it.

Most interesting to me is how involved Yang will be in the proceedings. Because, despite all the disappointment, the iconic Internet figure does still have a significant place in the hearts of his Yahoo troops.

But, even that has its limits and Yang is in more and more danger of truly losing those hearts and minds, especially if the company does not stop feeling like it is lurching from one drama to the next and very, very soon.

Said one former Yahoo who has been in touch with many still there and who still very much cares for the company (as most who have left truly do) about what the mood among current Yahoo employees is, in a common sentiment I hear often these days:

“They expressed frustration with the endless reorganizations and unclear future of the company. Also said that morale is really low and people feel like they aren’t seeing true leadership from the [senior] exec team.

“I definitely sense less sensitivity for Jerry in the conversations I have with people who are still with the company. Six months ago, whenever I mentioned that I feel sorry for Jerry (because I do) given everything going on, most people would nod or say, ‘me too.’ Now, the reaction is usually a groan or rolling eyes.”

As in: Boo!