"Wild Mood Swings is a simple game. You select a mood from a pull-down list, click on 'take me away' and it'll whisk you away to an appropriate site. Each time you reload the page or click the shuffle moods link, the moods are sorted into a different order."
(from The Presurfer)
UPDATED: Just for the heck of it, I've added a mood icon to my sidebar. Right this very moment, I'm "domestic". (I'd better enjoy it while it lasts!!)
You can also use automatically updating iMood "mood indicators" on your own blog, on your homepage or in your email signature, not to mention that there's a quick and handy little bookmarklet you can easily add to your browser which makes changing your iMood a snap!
(Want to see what mood the Internet has as a whole? Turns out that right now it's "tired"!)
In addition to letting you find other users, books, films, etc. by moods, the service also offers surfing via "Moody Links," which gives you sites submitted by those who've had the same mood as you do.
(Wouldn't you know it? There's nothing under "domestic"! Actually, can't say as I blame them...)