I took the source and compiled it, and finally, I didn't find it from the first try, but after a couple of tries I figured it up and ran 'ggl
The best thing was that, unlike Google Earth, this application is open-source, and the Linux version is offered as source, so you can take it, install the dependencies and compile it. The second thing I liked was the ability to build both Qt and GTK interfaces (or only choose one of them) for it.
There are digital clocks, weather gadgets, games gadgets, system info gadgets, practically anything you would like or consider useful on your desktop.
Well, first, I don't think it can compete with SuperKaramba or gDesklets, at least not at this point. Default sizes for gadgets are usually too small, cannot be configured, some of them don't work, and there is no transparency effect. It crashed for me with a segmentation fault just when I loaded the fifth or sixth gadget. It also crashed suddenly, without any apparent reason. It probably happens when trying unsuccessfully to fetch or load thumbnails for the gadgets' previews. But still, it's open source! And it's from Google! I always liked this kind of support and really appreciate it, not to mention it's cost-free.
If you decide to give it a try, here's the official project page.
Updated: June 10, 2008 (Created: June 10, 2008)