I had never researched this part of Mexico before. It is very close to Guatemala and Belize. I have tried to convince my brother to go to Belize and check out some places for me. It may take more convingcing... JF being a back-packer, we don't have the same taste in lodging : )
http://www.mexico.us/sancristobal.htm
Maybe showing off a little of Belize will change his mind. I haven't yet finished with the British Virgin Islands, but i'll make an exception! While i sit here, with a nice glass of red, i will dream about beautiful beaches and try to convince my bro to stop by one of these. So here's to you little guy, Cheers!
Belize...