Via Matthew Gallant though, here is a tip to instantly delete all your spam, or at least mark it as read so that you aren’t constantly reminded about it.
In Gmail, go to Settings->Filter->Create a New Filter. In the box for “Has the words:”, put “in:spam” (no quotes). Hit next, ignore the message. Then check “Delete It” or else “Mark It Read” and press the “Create Filter” button. Voila, no more annoying spam.
Another way to hide the spam is to just use another email client, such as Thunderbird. Gmail recently added support for IMAP access to your email from 3rd party email clients.