does anyone know of a good forum online for transplant patients?
You might want to look on the Life Options website for online support group links. There are a couple of transplant groups there.
There are also transplant groups on Yahoo Groups. Transplant_Friends has around 130 members, has been in existence longer, and is the most active of the ones there.
The Dialysis_Support list has members who have transplants and is a very active listserv with over 900 members.