Nice dude, I'm 16, built my first PC at 14. It was friggin sweet. I still remember putting all the stuff in and all that. It was fun.
You probably have a higher sense of accomplishment, seeing as you saved up for it yourself, whereas I convinced my parents of the various advantages to having an up-to-date system.
I look forward to getting a few cheap OEM workstations to play around with in all their 24" sony trinitron goodness, as well as building a new one sometime.
Ah, I remember the 1TB machine I built for my uncle this year...That is a freaking nice machine. It gives me a real kick when I see 0.3% hard drive usage Guess he hasn't put his digital video on it.