This is my latest and greatest thrift-store find. A pair of BB green seersucker shorts:

Check out Giuseppe's blog "An Affordable Wardrobe" for some great discussions of thrift shopping. He usually manages to find some great stuff up there.
Also, take a look at Patrick's blog for more crazy finds. Patrick Sullivan. Also check out his old blog "Coiled Pleasures," which thankfully still has its archive up, to see even more great finds.
This thread over at The Curriculum has tons of great finds.
Head to your local thrift store and see what they have. You never know what you'll find.
Conor