Well, I was thinking Buddy was about 6-9 months old but the vet that neutered him said he's closer to a year old. I'll probably give him a "birthdate" of April 7, 2010.
don't really know as they are all rescues, but our youngest is hitting the 5 year mark with us--she's an Easter time bunny dumped in a park at around six weeks. She weighed less than a pound and now is 9 pounds. We have a couple that are probably close to ten (or older), but they are all rescues so it's anyone's guess.