Some time ago, I copied Michael Casey and talked a bit about Desktop on Demand. Since then, I've been playing around quite a bit with a similar application - Goowy. Goowy and DoD both operate as a home-away-from-home desktop environment, but there are a few differences.
Goowy does not run its own browser (rather it just runs in yours), does not provide anonymous IP addresses, and it doesn't come with a word processor. But what it does do is work. Goowy is easy to get started with, it's quick, and it does what it says it's going to do. It provides email integration, IM integration (with Yahoo, Gtalk, and other Goowy users), calendar, contacts (importable and exportable), favorites, an Mp3 player, and my favorite part, online file saving/sharing. The file saving is powered by Box.net - but the funny part is that it's actually easier to use through Goowy, and you get a free 1Gb vs. having to pay for 5 Gb when going directly through Box.net's site.
I admit that I have my "online life" pretty well set-up from both home and work and don't have too much call to use Goowy, but since I do work from home occasionally, I use the online file saving feature to make life easier.
However, I would love to offer a class on Goowy to patrons. Many of our patrons use the computers at more than one library, and I think Goowy would be a boon to some of these people. Also, I have found that the IM feature works on our computers - and even Meebo doesn't work on our computers, since we have chat clients blocked. Gasp! Am I suggesting a work-around to our system? Yes, yes I am. While I hope that someday we will unblock at least Meebo, in the meantime Goowy would provide a chat/IM option that doesn't interfere with our network and doesn't require a download.
A patron could also check all of their email accounts from the same place (we don't offer a tabbed browser), and even play their own music without having to have their iPod (or whatever) with them, as the music files are stored - and played from - the patron's online files. There's even a "minis" feature, which uses a number of widgets and sets up very much like iGoogle or Pageflakes. All from one window.
Desktop on Demand may have been one of the first to this particular party, but I have found Goowy to be infinitely more usable - especially on a public computer.