Cruft that builds up on blogs
I was using the excellent FireBug add-on on my own site here. It really shows the crap you can quickly build up. I noticed that the meebo widget and MyBlogLog tracking were both eating up over 80% of page load time. Since I hardly ever use that stuff, I turned them off.
Quantcast and Google analytics were allowed to stay, since they use a very modest amount of load time.