A jungle trek from Chang Mai is well worth the effort. Some of the scenery from up in the hills is breathtaking and an excellent chance to get a little bit more of an insight into the rural landscapes and lifestyles that cover so much of Thailand. Don't worry if your not much of a walker, we did a couple days trek and didn't walk for much more than 2 hours a day. A fair bit was done on a wooden raft and on the back of an elephant! Most guesthouses and travel agents in the town will be able to sort out a very reasonably priced trip incorporating what you want to do, and will even pick you up from your accommodation.