quite frankly, the lifespan of a system is long enough that it doesn't matter whether it is left on or not anyways. I leave both my systems running 24/7, and the original I used to run as well (Pentium @ 133Mhz, 32mb RAM) was on for a total of 6 years (i owned it for 7, but lets just say that it was "on" for 6, for argument's sake), then that would mean 52,560 hours of runtime. If you want more than that out of a PC, then I think you're dreaming.
And for anyone whose interested, it died about 4 months ago due to motherboard problems :*( ... though it now exists in the heart of three working computers (I saved the CPU and stuck it in a mobo that had a P100 and OC'ed it to 200 with a cooling mod, stuck the hard drive in a 266Mhz MMX OC'ed to 333Mhz system as backup, the ram in both, heh, and the sound card (original SoundBlaster 16) and the video card (Voodoo 2000) into a P233Mhz (OC'd to 266Mhz, too unstable otherwise). The beauty of cannibalizing old systems is the fact that you can have an oldschool Lan-party without anyone needing to bring a thing ! plug in to the Hub and you're off ! heheheheh, also gets pesky family/friend/girlfriend off back when they want to use the internet or do "work" while you're on the main rig, hehehehehe
<b>"Feminism is the radical notion that women are people"<b>