On average, computers last me for about 4 years. Last week, I was still using an 800MHz iMac. Partly this is down to my being frugal. It’s like the TV situation, where I didn’t buy the HDTV until my family visited and laughed at the 20″ TV, and seemingly made it die of shame shortly afterwards. Partly it’s because Macs remain usable longer than PCs. A PC Magazine survey found that Macs tend to last 3.