Already Upgrading the Development Server
Apparently, that was much more of an antique than I thought it would be. We're now running a Hyperthreaded P4 with 2GB of RAM and hardware mirrored SCSI drives. I thought that the old machine would just act like our web servers under heavy load, but when it was taking 2 minutes or longer just to load a couple fields via Ajax calls, I decided that wasn't worth waiting for any more.
Now, I'm going to be able to develop a little quicker... and I've got some sweet projects planned out. When I get them a little further along, I'll be sure to let anyone reading here know about them.