Getting into KL at 2:30pm back out again about 9:30pm.

Any tips of things to do around the airport?

Bring a laptop

Free wifi in airport

Nothing to do in or around airport

eat eat eat and have a coffee while you surf

First, and most important question: At which terminal do you arrive ?

If at the LCCT (being used by AirAsia), not a lot you can do within 5 hours. getting to downtown is too time-consuming and risky.

If you arrive at the main terminal, you can hop on a KLIA-Express, which does the 70 km in 28 minutes. cost 35 RM one-way, but as far as I know, if u do the return trip the same day, there is a big big discount.

arriving at KL SENTRAL station, hop on the MONORAIL (a walk of 7-8 minutes involved, as there is a big construction-work going on in front of KL-SENTRAL at the moment) and exit at BUKIT BINTANG stop, which is in the middle of the shopping district, plenty of giant malls (Pavillion, TIMES SQUARE with a fullsized roller-coster plus plenty of fun-rides between 6th and 12th floor), plenty of restaurants, Cafes, and whatever you may want.

First, and most important question: At which terminal do you arrive ?

If at the LCCT (being used by AirAsia), not a lot you can do within 5 hours. getting to downtown is too time-consuming and risky.

If you arrive at the main terminal, you can hop on a KLIA-Express, which does the 70 km in 28 minutes. cost 35 RM one-way, but as far as I know, if u do the return trip the same day, there is a big big discount.

arriving at KL SENTRAL station, hop on the MONORAIL (a walk of 7-8 minutes involved, as there is a big construction-work going on in front of KL-SENTRAL at the moment) and exit at BUKIT BINTANG stop, which is in the middle of the shopping district, plenty of giant malls (Pavillion, TIMES SQUARE with a fullsized roller-coster plus plenty of fun-rides between 6th and 12th floor), plenty of restaurants, Cafes, and whatever you may want.

With 7 hours between flights you should be able to take the bus even from the LCCT. iirc, it's about 8-10RM each way. Or, you can take the shuttle bus from the LCCT to the main terminal and then the KLIA-Express. The shuttle bus between terminals costs about 2RM and takes about 20 minutes. otherwise I can't think of anything else to do other than what Siam mentions.