How to avoid Air Asia's hidden charges
Air Asia is a great low fare airline with punctual departures and descent comfort. You get a good return on the few money you spend, but beware! In order to keep their prices low (it seems) they charge you extra whenever they can. This is what you might experience.
Booking the flight
At two different points when ordering your flight ticket online at AirAsia.com you will get a "hidden" additional cost. First, when you search the system you will see a certain price which can be VERY low. This cheap price, however, can be up to 5-10 times higher when you click Next. Typically it adds 50 - 100 % on the price.
The reason for this additional cost is that AirAsia adds Fuel surcharge, airport taxes etc after you have clicked next. This is very annoying because it makes it harder to compare prices.
The second "scam" you should look out for is when you are about to check out. In the last step AirAsia will add an insurance to your itinerary. This insurance you will have to actively deselect by clicking "No Thanks" in your left column. The you click Cancel in the pop-up box. I have no idea about what the insurance is good for but just by the fact that they have to sneak it in makes me very suspicious.
AirAsia recently (2007) lowered the luggage weight you are allowed to carry to only 15 kg! They charge you a lot extra for every additional kilo as well. With only a few kilos extra you are almost paying as much as the flight ticket! The carry-on is 5 kg and will typically not be checked so if you end up with too much you might be able to rearrange your heavy stuff into your carry-on. Don't count on this though! If the carry-on is too heavy (and they find about it), you might have to throw away the excess weight.
Normal low-fare airline inconveniences
Except for the "scams" mentioned above, AirAsia is a very descent airline. You will find one of the lowest fares with them. Prepare however for, like all really low fare airlines, AirAsia typically lands quite a bit outside the city in most destinations (such as Kuala Lumpur).
Food is only available during the flights if you pay for it so bring cash or your own food!