they should come out with a keyboard with "www" as a single key. if it's not already out, remember where and who you heard it from first.
It's a good idea for those who manually type in all the sites they go to. It wouldn't make a difference for people like me who find their sites via links, favorites, and browsing.
who actually types www into the browser bar?? not me. who actually types out links when chatting or posting?? not me. I think most people copy and paste an address, instead of typing the thing out.