Cindy Sheehan says in an interview (audio) that she regrets calling George Bush a "lying bastard:"

The discourse in our country is oftentimes not productive. I believe that I did engage in some of that before. I'm trying really hard to keep my language better than it was before.

You asked me if I regretted anything, and I just thought of something I regret. I regret calling George Bush a lying bastard. I don't regret saying that he lied, because it's obvious that he did, but I regret that heavy rhetoric and that language that I used.

But that was a long time ago, when I was still very...very angry and bitter. I'm not bitter anymore. I'm still angry, and justifiably so, but I'm not bitter, and I regret that language and I regret when other people use it too.

So I think that our rhetoric has to be a little more loving than their rhetoric, because we can't fight hatred with more hatred, we have to fight it with love. And we can't fight violence with more violence, it has to be with peace. So I've become more peaceful inside myself, so my actions and my language can be a bit more loving and peaceful.

The entire interview 20 minute long interview can be heard here.