My top picks. Super cool causes, check out their websites regardless of whether you're feeling philanthropic:

  1. East Coast Greenway: building a continuous non-motorist route along the entire Atlantic coast [precisely my route]. The trail is partially done [and I have been utilizing it], but unfortunately it'll still be a while until I can ride up the east coast with no fear of being hit by a car.
  2. Vasalgel via the Parsemus Foundation: a reversible, long-term contraceptive for men. I could soapbox for days on what I think the profound social implications of this would be!
  3. Sunlight Foundation: dedicated to creating transparency and accountability in our government by unearthing the specifics on who's paying out our politicians. 

Local organizations I've visited and/or donated to on this trip [psst, if you'd like to suggest a local charity along my route, drop me a line]:

Key West Wildlife Rescue in Key West, FL, is refreshingly transparent [you can visit for free, but the center is decidedly not oriented towards tourists, but on their actual stated mission...]; rehabilitates and releases local birds and other animals.
The Turtle Hospital in Marathon, FL is quite sophisticated; rehabilitates and releases threatened sea turtles [like them on Facebook for updates!]

Also, I highly encourage researching local charities in your area!

Some that I like [in California and Nevada, two of my main stomping grounds] are Reno Bike ProjectChrysalis Community Counseling ServicesCommon VisionUrban TilthRichmond Trees.

For larger charities, check out the listings on Charity NavigatorCharityWatch, and the BBB Wise Giving Alliance, who all vet charities for effectiveness, transparency, etc. and categorize them so that you can find a cause in support of something that speaks to your own values and hopes.