I'M iniative extended to Hotmail

The i’m™ Initiative from Microsoft™ makes helping social causes easy. Every time you use Windows Live™ Messenger or Windows Live Hotmail®, our free webmail service, we'll share a portion of our advertising revenue with some of the world's most effective social cause organizations. Exactly how much will we share with our partner causes? Well, that’s up to you and the growing masses of registered i’m Initiative users. The more messages you send, the more we give.
Now the small things you do every day, like e-mailing and IMing, can make a big difference.
Details here