Good ideas for a charity event to raise money for organizations?

I used to offer carwashing services to any donor who come to our blood donation drive. I only charge them $10 and will also give hem a keychain right after. When I'm inside the blood bank, I offer lectures about donating blood. These lectures usually last thirty minutes or so depending on the length of discussion. Then, when the lecture is done, I gave 50% discount to those who buy a complete set of the kit (an original DVD of a documentary film, a free membership to a blood bank, a lecture manual and a keychain). Why not call a blood bank, help them organize a blood donation drive and let them teach you how to fundraise more money? This way, you are not only encouraging some people to donate blood. You are also helping the bank earn money to fund their operational costs.

Sponsor a dinner with some kind of speaker; maybe you can convince some local public figure, like a politician, or you could have a story night with the dinner entertainment being stories read by kids who wrote them.

what are you raising money for? that makes a huge difference in the answer to your question.