If you use MSN/Windows Live Messenger for your IM you can add a code to your display name that will raise money for a charity every time you send a message. How cool is that?
All of the info can be found here but I repeat most of it for you.
First you need to upgrade to the 8.1 version of the software which you can get from here
Second add one of the following codes to your display name (you might was well add it to the end)
American Red Cross = *red+u
Boys & Girls Clubs of America = *bgca
National AIDS fund = *naf
National MS Society = *mssoc
ninemillion.org = *9mil
Sierra Club = *sierra
StopGlobalWarming.org = *help
Susan G. Komen for the Cure = *komen
UNICEF = *unicef
Every time you IM some money is donated to the charity you used in your display name. Microsoft is donating a minium of $100K to each charity but your IM’ing can boot it above that.