I've never actually notably damaged anything; but I'm very glad I took static precautions in one instance: My friend's laptop had a bad DC jack, and the official repair chaps wanted something like 500 for a new motherboard. I figured that it was worth attempting a repair, as the machine was useless otherwise, and hardly worth the cash to fix. This was my first ever laptop, and not mine, so I decided to be really, really careful. Worked on a grounded aluminum table, with wrist strap. As I clicked in to begin work, I got perhaps the worst static shock I've ever had. Luckily, that was the only static of the entire operation.