It's completely free to you - you choose the charity, they donate the money!
I am asking them to send $20 to the Hands and Feet Project in Haiti.
So here's how you can help:
If you have a blog, mention Hotels Combined in a post and they will donate $20 to your chosen charity (just email them with the URL and your chosen charity).
If you become a fan on Facebook, Hotels Combined will donate $5 to your chosen charity (simply sign into Facebook, become a fan, then post a commend on their Facebook profile indicating your choice).
And if you twitter about them, they'll donate $10 to your chosen charity.
Giving to worthwhile charities or ministries can't get much easier than that!