Alright, here are my suggestions for some RAM, depending on how much you want to spend.
Value RAM - G-Skill Value Series (2 x 1GB)...$148
If you'd like to spend a little bit more, this Muskin RAM is very nice.
Mushkin PC4000 (DDR 500, 2 x 1GB)...$199
Currently that Mushkin is on sale with a mail-in rebate for $199 at newegg. There is a review at www.xtremesystems.org
that shows the Mushkin EASILY reaching DDR500 speeds, and many times going up to 260 MHz or 270 MHz. If I had to buy RAM right now, I would go with the Mushkin.