I’ve been using Gmail for quite a while (would you like an invite,… drop me a line?). It’s really quite a good system, though I’ve had difficulty getting used to several features. There’s quite a difference between Yahoo! mail and Gmail…
No folders… Gmail uses labels
Archive function … helps to clean out your inbox
2GB of space… in fact, there’s more
POP and forwarding features… these are only partly free in Yahoo!
Stars… you can highlight important emails.
Effective Spam filters
Inline conversation or threaded emails … keeps context easy to understand
i’d give it four stars out of five for the above features and usability. Great softare. And the ads… I’ve not found them very intrusive, and sometimes I can keep click on them, if they are interesting… An invasioin of privacy? Well, I don’t find that to be a problem, Google never sends me uninteresting or regular emails, like Yahoo! does. So it’s a small price to pay in my opinion.