I hardly even bother. I'd been known to just toss the computer and perform surgery FROM BED IN MY FUZZY SLIPPERS if I had to -_-. OK, that's a little overboard, but I did once ;p.
So in conclusion, it doesn't really matter. My brother says it's partially due to the elevation I live in (at or under sea level...) so if you're in Denver of something. You may want to invest in a strap, anti-static mat AND do your tinkerings IN YOUR GARAGE, not in your fuzzy, carpeted room. Oh, don't try it with plushy pjs on either ;p. BUT how hard is it to get a strap?? I mean... where a freaking WATCH! or a friendship bracelet! 10 cents at the country grocerie store. seriously. put some paper down and don't drag your feat. I mean, it's not a matter of expense. your just LAZY. *and so am I ;p*