The Daily Beast has a good list, with donation links, of many NGOs on the ground in Haiti that you can pick from to help out*. (Map right from Lonely Planet.)
Please go and have a look, and make your choice.
If you’re really too busy, consider the texting options. You send a text message to a number and it results in a donation that is later deducted from your phone bill. A pair of examples:
Text HAITI to 90999 ($10 to Red Cross)
Text YELE to 501501 ($5 to Yéle, Wyclef Jean’s development organization.)