yes, in 1993 i went to cayo. there are some really excellent chinese resturants in san ignacio.
i stayed at banana bank ranch, and they are known for their horsebackriding stables. you can contact them for a day ride. also, i saw the rio frio cave, i thought it was absolutely awesome (by it's true defination, not the slang). then we trotted into the river pools (brrrr). we also saw the thousand foot falls, and it was a terrific adventure.
we had rented a suzuki sidekick that year and drove ourselves around. absolutely had a blast. the "inland" blue hole was neat too, but lotsa 'skeetas there.