isnt this called sun worship (or something like that), i saw a lemur doing at borth animalarium and im pretty sure steve irwin (in one of his programs) said that it is sun worshiping
All Ring-tails seem to do it, it's sometimes referred to as the Lotus Position, or indeed, 'sun-worshipping'. It's supposed to warm them up after the night, also I reckon they just enjoy it like this one obviously does!