I boycott Wal-Mart and do preach about it. I think at this point with that though, everyone has figured out that as you sow so shall ye reap. (i.e., everyone in my bassackwards hometown was excited about getting a Walmart, they got one, it put everything else out of business and now everyone bitches about it) Unfortunately, for some people it's the only option in town for affordable clothing and home furnishings.
I boycott a couple local bars that are just generally unpleasant, and some of those are racist and homophobic on top of it. I'll share these opinions with anyone who sits still long enough to hear them.
I also don't buy "pink" items. Looking forward to seeing this movie this week:
http://www.moviefone.com/movie/pink-...541/main?flv=1