Computer years?

If a dog year is equivalent to seven human years, what is the equivalent of computer life? 20 human years for every computer year? 25? I have a laptop that is showing its age. It hasn't worked right since it came back from repair a month ago. It freezes intermittently when I am typing. Apple blames the 3rd party memory that I say worked flawlessly for 18 months before this last trip in for repair. I think it has something to do with the keyboard or mother board. Thus, not much activity on this blog, and I am way behind on e-mail since returning from New Zealand. I guess I can blame the Holidays also. As I wrote earlier about my laptop addiction, it is really hard to be without a usable laptop. I have decided that I will need a backup when I get my new one, maybe during MacWorld. I've also asked Santa for a Bluetooth keyboard that will work with my PDA and my computers.