Give Puppy a try. Basic functionality in a very small package. There are flavors that have a slightly larger footprint with more features.
Basic Puppy
Some other versions linked to here:
http://www.puppylinux.com/other.htm
You beat me to it - Puppy is amazing for a small distro that will run like crazy on limited hardware.
I like Puppy too. I bought my dad an old 700 mhz laptop with 128 mb of ram. Puppy runs on it like a champ. He uses it every day, mainly for getting on the Internet and light word processing. He can even share files with his Windows XP computer through the network.
I have just under $100 in the whole deal, including the wireless card.
Puppy Linux is great for the old machines. I use to boot up with a CD and save stuff on a memory stick. That way the computer I used was unaffected but still set up just the way I liked it.