I have a Dell Dimension 8200.
-2.0 ghz pentium 4
-256 mb ram
-40 gb hdd
Next time around, probably this fall, I am going to build one myself. I have to keep it relatively inexpensive, so I can afford a nice tv for my PS3 next year. So I'm afraid no 7800gtx I'll most likely have to "settle" for a x850pro, they have those for $300 on newegg, by the way.
Good lord... I hope you build something nice. I suppose a toaster would be an upgrade.