Still, the Refresh link in Gmail is probably your friend. It is mine, too. I don't use it, however. Spoiled by Gmail's many useful keyboard shortcuts, I refuse to take the fingers off the keyboard and check for new mail with the click of a single key as well.
Check Your Gmail Account with a Keyboard Shortcut
To check your Gmail account for new mail with a keyboard shortcut:
- Press u (think "update").
You can also check other Gmail keyboard shortcuts while you're at it.
(Updated October 2012)