Gmail is pretty slick, but if you've never gone poking around in your settings menus you really are missing out.
Settings can get a bit scary, but the trick for today is to head straight for the Labs menu. This is where some of Google's cleverest add-ons to the Gmail and wider Google Apps experience are hiding. Everything from giving yourself a chance to cancel a message after you've hit send, to stopping yourself from sending email when you're intoxicated, to hiding unread email counts so you don't get upset at how bad you are at keeping with emails.
Just hit the cog in the top right of the screen, then Settings, and then Labs, and try out a few new features.