I downloaded Prism yesterday , and I've only used it once. Basically right now , i can describe it by saying, its like an IFrame container for any webpage that installs an icon on your computer. Its nothing cool, or nothing wicked like AIR. I mean i do see the use for it, im using it right now to check mail and stuff, but then thats why thunderbird is there. I really don't see a big use for this , unless im missing a whole chunk of functionality i haven't touched yet.