There’s a great bundle currently running on the Humble Bundle site at the moment with a number of really great games (and the Stanley Parable to keep thing balanced *snigger* )
For $30 dollars there are some great games there, but as you can see from the screenshot above. Some of them are starting to run out of keys. So get your skates on if you want to take part.
And that it’s helping some great charities is just the icing on the cake.