Yes, Windows is a resource hog.
Right because the 350 MB that 7 is using on my laptop right now is soooo much memory
My quick take on the "which lightweight linux" discussion:
Puppy isn't nearly as ugly as DSL, but DSL is about as lightweight as they come.
gOS is pretty decent. Tried it once, everything worked pretty well by default (though that's generally true of Linux on older hardware anyway) I have no idea about support for any of the advanced Google stuff JMad uses.