Or even go for a Buffalo Linkstation -- http://linkstationwiki.org/ -- which is essentially a kurobox (200MHz PPC, 64Mb RAM) with a disk (160-250Gb) already built in.
It's really intended as a NAS, but it's relatively easy to install debian on it. I'm very happy with mine.
Slashdot Mirror
It's really intended as a NAS, but it's relatively easy to install debian on it. I'm very happy with mine.