Remember the Humble Indie Bundle and the Humble Indie Bunde 2? 
Now there's a new games fundraiser, the Humble Frozenbyte Bundle - named after the developers who've donated their hit game Trine and other titles including Shadowgrounds, Shadowgrounds: Survivor, Splot and Jack Claw. Games (except Splot, which is still in development) are all available for PC with Mac and Linux versions either available or promised to arrive soon. The Frozenbyte FAQ details what's required, Steam availability, limitations and future plans.
As a bonus, Trine, Shadowgrounds and Shadowgrounds: Survivor all include the soundtrack MP3s, while Jack Claw offers an editor with assets and source code.
As usual, you can donate as much (or as little) as you can to benefit Child's Play and/or the EFF (your choice or split between the two) as well as cash to support the games' developer and the Humble Bundle folks who made it all happen. Settle up with PayPal, Amazon payments or Google Checkout.
Only a day in, and it's already raised nearly $500,000 with the average donation at $5.15. Linux users are the most generous, averaging nearly $12 per bundle.
Unless extended, this offer ends on or about April 26 - so do some good, and get some great games!
Throughout the year I always do these little things to get some money toward Child's Play. Will definitely be picking this one up for the third year.