I may have to give gOS a try - I use a lot of Google applications myself, as well as Facebook, Meebo and Blogger, so it might be useful. It certainly sounds like the ideal OS for your grandma, and completely blows out of the water the old complaint that Linux is hard to use - the only reason people EVER say that is because they have to install it. Believe me, Windows XP is actually a harder install most of the time than any Linux distro.
I've mentioned previously why I think Linux will profit from the growth in use of web-based applications, and the immense popularity of gOS is showing this better than anything I could have said. If you use web-based apps, then performance is going to be better on a lightweight OS than a bloated monster like Windows Vista. These PCs with gOS preinstalled are not very powerful, but because they use gOS they're still fast enough.
Blogged with Flock