At what temperature should I start worrying?

Heh, you just know I'm probably already kind of high if I'm asking that. I've got a pretty sorry fan on my 1.2ghz Athlon and my CPU temperature is about 51 C when idle. Since my current fan is incredibly noisy and the CPU temp bothers me I'm trying to get one of those Silverado coolers. It's going to be awhile before I can get one of those though and I'm wondering if just normal computer use could damage my CPU. What do you all think?

If you're only planning on using the same processor for a maximum of 3 years, then don't worry about the temperature until your system becomes unstable (i.e. crashes/lockups/artifacts). If you will be using the computer for 10 years, then you will have to get medi-evil on heat.