Now in its fifth year, it was called “Making a List: The Fifth Annual What’s Hot and What’s Not in Personal Technology” and took place in Palo Alto, Calif. Our guest were Marissa Mayer of Google and tech consultant Greg Harper.

Walt and I typically show off several devices we think are interesting and try to identify some important trends.

Here’s a video of Walt, Greg and Marissa at the event:

(I still am having problems with the Brightcove player, so I uploaded the video to YouTube.)

For example, Walt showed the new Amazon Kindle electronic book reader (which he did not actually like so much in his review of the device this week), as well as the new version of Sony’s e-book offering. He also showed some new cellphones that are trying to mimic the Apple iPhone. His take: Great software in consumer electronics is key this year.

I showed new robotic devices from iRobot–the new version of its popular Roomba vacuum and its new wireless gutter cleaner called the Looj. We had an actual gutter on stage, full of leaves I made my much-abused assistant Ed Daly collect from a gardener’s truck we found on a suburban street.

And every year, we’ve brought in uber-gadget geek and tech consultant Harper, who always brings in a truckload of cutting edge and sometimes freaky stuff. That included an egg-shaped speaker that dances from, of course, Japan, as well as a solar battery charger, a $400 laptop and a vanity mirror that is a Webcam in disguise. Harper posited that all devices would have to be always connected going forward.

And, also annually, we invite a celebrity geek from well-known tech companies. In the past, we’ve had Google’s Larry Page, Jerry Yang of Yahoo, RealNetworks’ Rob Glaser and Chad Hurley of YouTube–geeky guys all. But Mayer, one of Google’s top execs, proved the nerdiest with a wide range of cool stuff.

She showed off a keyboard whose keys had embedded LCD screens, a wireless rabbit, an alarm clock that can jump off your nightstand and a T-shirt with a wireless signal locator in it. She also did a demo of exactly what the new Google Android operating system for cellphones looks like. Take careful notes: It looks an awful lot like the iPhone.

So far the reviews have been less than whelming–too clunky, too pricey, too wonky, to name a few of the complaints–but it’s interesting that tech types keep at their seemingly futile effort to replace the very useful device known as the book.

At D4, for example, Sony head Howard Stringer (pictured below) declared its $350 eReader was going to be a big hit. It was not. (Well, to be fair, he did not give an exact timetable on the success of the gadget, but we’re still waiting.)

So far, the meek little book still seems to be the winner over all e-book challengers.

Why is that, given the relentless digitization of every bit of content on the planet and the inevitable march in that direction?

I’d say it’s pretty simple. Books work fine–they are portable, cheap, easy to read, their batteries never die and they’re kind of pretty.

The pluses of an electronic version of a book are not so much of a plus. It’s portable, but not more so than a book. It’s expensive. It’s complex to figure out and sometimes not so easy to read. Its batteries always die. Also, let’s be honest: Not so pretty.

And, though you can hold more books on them–the big selling point–who usually is reading more than one or two books at a time? The same is true for searchability–unless it is a textbook, I can’t think of a time when I really wanted to search a book.

Still, the efforts to storm the castle of reading continues, as you will see here: