CentOS isn't all that bad. I've been running CentOS on my server since March or April with a heavy load of site traffic all that time - no problems at all so far.
Debian is another distro that I've been wanting to get my hands dirty with for a while, especially with you all always speaking so highly of it.
DanielJay, your server uses DDR2 memory, right? HP currently has a $40 rebate on some 1gb DDR2 667 modules. You can get them at TechOnWeb for $16 after the rebate and can get max of 5 rebates. So, 5gb for $80 + shipping and tax if applicable. It's quite a good deal & I'm thinking about getting that just in case I need more RAM at some point. The rebate is with HP & the RAM has a 1 year warranty. TechOnWeb shows today as the last day to buy with the rebate, although the rebate form has July 31st listed. Anyhow, here's the link if you're interested:
http://www.techonweb.com/products/pr...aspx?id=D30292