One more thing to note, you have to turn Forwarding / POP3 on inside Gmail, go to your Settings inside your Gmail account and see this tab: Forwarding and POP
Make sure you have this enabled to use this feature! (In Yahoo you have to pay for this feature

)
Edit:
Some may have issues with the logging into gmail, but make sure your firewalls allow the following ports per Google:
http://mail.google.com/support/bin/a...y?answer=13287