They guys at mariomarathon are raising money for child's play, and they need your help. They've raised over 40,000k for child's play, and are not stopping until they run out of sponsored levels. The more you donate the longer they play, so donate what you can!
Level checklist: http://www.mariomarathon.com/goals.html
Contest and prizes: http://www.mariomarathon.com/prizes.html
Go show them GWJ's kind kind heart people!
(Hope this hasn't been posted before, searched a bit)