I just picked up a set of them at Campmor this past weekend, but haven't put them on the bike yet. I finally bit the bullet and got them after having to go into the grocery store last Friday with stripes up my back and front, just from a little drizzle.
I also got the planet bike ones - plastic with the little mudflaps ... they're surprisingly light.
A word of caution about puddles, though: It's still a good idea to avoid them - you don't know if there's a major pothole under there, and you could take a nasty tumble.