Us miners smack the crap out of our hardware, pounding the video cards for weeks at a time. Here are some to
tips to maintain the health and lifespan of your hardware:

1) Take periodic breaks for mining. Perhaps every hour in 12 should be "down time" with no mining.
2) Try and keep the room extra cool, perhaps put a fridge in the mining room with the door open
3) Provide your card with warm up and warm downs, gradually lowering GPU speeds
4) Avoid getting foodstuff, jam etc, in your hardware. Same goes for drinks
5) Cigarette smoke has been shown to damage fan parts - don't smoke fags near your PC if you care!
6) Take the occasional weekend off, only playing minesweeper to calm your video card.

Anyone gots any more tips I'll be glad to add them to the list.