If you wish to help, please consider buying a t-shirt from the following sites that are offering a percentage (as high as 100%) of the proceedings to Haiti relief funds.

Halo creators Bungie, have a very cool Be a Hero T-shirt with profits going to the red cross and Haiti:

The folks over at CafePress have a Haiti Relief store with some very nice t-shirts and all profits go out to Haiti relief:

I Love Haiti Fundraising Shirt from the people at Herbivore Clothing. They will be donating 100% of all sold T-Shirts to Haiti:

Feed the Hungry T-Shirt from Pyknic Clothing will be donating 75% of sales of this shirt to the people of Haiti:

These are just to name a few, you can check out some more help Haiti t-shirts on Coty Gonzales, Tcritic and Hide Your Arms.

If you can donate money, google has set up a website with links to the major humanitarian organizations aiding Haiti.