I generally don't pass forwards on, but I checked this out and according to snopes.com, it's a legitimate fund raising project. This describes what it's about:

I have a favor to ask, it only takes a minute....
* I * 6 * Y
Please tell ten friends to tell ten today! The Breast Cancer site is having trouble getting enough people to click on their site daily to meet their quota of donating at least one free mammogram a day to an underprivileged woman. It takes less than a minute to go to their site and click on 'donating a mammogram' for free (pink window in the middle).
This doesn't cost you a thing. Their corporate sponsors /advertisers use the number of daily visits to donate mammogram in exchange for advertising.
Here's the web site! Pass it along to people you know.

www.thebreastcancersite.com