Remy,
I don't have a router right now either, so I keep a p3550 offline. I've been able to store up to 150 candidates on mine when I set the cache to 100. Depends on your machine, but the 550 only does maybe 15-20 a day so I don't have to dump for up to a week. When you do go online make sure to wait at least 10 mins. for it to download new clients then upload the candidates you have processed. Also the results may not appear immediately on DDol stats(usually another 10 min).
Also, Linux seems the way to go, somehow it seems to be more efficient with the java based client. I've seen people claim up to 75% better than windows. I don't know personally, but will be installing Mandrake on the pentium this weekend to find out.
Anyhow, It is a pretty cool project(I guess it's not cool it's needed) and our recent surging in the ranks is making others take notice. I've browsed other team boards searching for tips and TeamAnandTech is being mentioned alot. Good Luck.
Peter