The Twilight Saga: New Moon and The Twilight Saga: Eclipse star Rachelle Lefevre joined Twitter a while back and issued her own Twitter challenge (amongst the Peter Facinelli/Rob Defranco whirlwind), offering to give $100 for every 10,000 followers she got.
At this point, Lefevre has almost 55,000 followers, and she has already made donations to the Susan G. Komen For the Cure charity - as have many of her followers.
As part of the challenge, she asked her followers to visit The Breast Cancer Site saying "click the pink button (it's free) to help get corporate sponsers to donate free mammograms to women in need."
As of the latest count, about 45 donors (including Lefevre) have contributed to the fund raising more than double ($2,367) the initial goal listed ($1,000).
Donations (both personal and follower-based) are still being accepted for the challenge, and you can donate here and follow Lefevre here.