I just love the website for Mental Floss magazine. I found it kind of by mistake, but it's a Trivia magazine and the website is full of Fun Facts to Know and Tell. They have a daily "Five Questions" feature, with five questions on a single theme (e.g. yesterday was Paul McCartney's birthday, so they were all questions about him). And the T-shirts! The absolute best silly/funny/geeky t-shirts. Some of my favorites:
Hokey Pokey Anonymous: A Place To Turn Yourself Around
Veni Vidi Wiki: I came. I saw. I edited collaboratively
The Constitution: I read it for the articles
And a math one that doesn't work unless you see it.
I want them all! And the magazine, too.