I have several:

1 Custom computer with an Intel Core 2 Duo, 4 gigs of memory, 500 gigs in RAID 1 (mirroring). This is my pc, and is currently running Vista.

1 Lenovo Thinkpad Z61 (for work) with a 15.4" widescreen, 100 gig sata hdd, 1.5 gigs of memory, a DVD burner, and an Intel Core 2 Duo chip. Its pretty fast.

1 Custom computer with a Pentium 4 3.0 chip, 4 gigs of memory, and windows server 2003. This is my domain controller, dns server, and web server.

1 Custom computer with Pentium 4 2.8 chip, 1 gig of memory, and a 200 gig hard drive. This acts as my test box. Right now it is running Fedora Core.

1 Custom Computer with a Pentium 4 2.8 chip, 2 gigs of memory, and a RAID array with 1.5 tb of storage. This is my file server. Everything important gets backed up nightly, and everything weekly. This is then backed up to tape.

I have several others lying around, but I think this is all I have live right now.