I seem to always write recommending food, but anyway here is another: In Phnom Penh there is a great restaurant called Friends.  It has nothing to do with the TV sitcom but is a non profit restaurant which is staffed by street kids who are training to become chefs and waiters.  Food is top class and the service is even better, check out the website here, also while in Phnom Penh you must go to the Russian Market for great shopping, best buy is GAP clothing.