I just added a link to Kiva. We just made a new loan to a single mom in Peru. My niece and her fiance are in Peru right now. They are heading to Pico, Peru to help rebuild after an earthquake destroyed half of the community. My Mom is talking about going down with my sister to meet up with Robin and Jun and work at the project.
If you are like me and can't hop on a plane, fly to Lima and ride a bus for a day or so to Pico so you can spend your time and money volunteering on your holiday, Kiva is a great alternative.