Be Freezin for a Reason and take the Plunge for Special Olympics February 18. It's a great event. You earn pledges, jump into lake Monona and get a sweatshirt if you've raised at least $65.
If you go to http://www.specialolympicswisconsin.org ... plunge.asp you can register online and get a personalized web page where you can collect credit card pledges and add a photo.
There's hot tubs and heated tents on site, which makes the whole experience a lot more bearable, but you can still tell your friends "Yea, I jumped in a lake in Wisconsin in February ... on purpose."
Last year 1,711 took the Madison Polar Plunge, making it the largest Special Olympics Plunge in the state.
If you've taken the plunge before, please reply to this post with your stories. Personally, I've done the Plunge once in Wausau and once in Madison. The hot tubs help. So do aqua sox.