The low cost carrier terminal (primarily an Air Asia hub) in Kuala Lumpur offers free WiFi at its international departure lounge.
[Update 17th April 2009]
If you are transiting via Kuala Lumpur, you can get a transit visa (provided you hold a Passport under the list of Countries that are eligible for Transit pass) at the LCCT or KLIA. The transit visa desk is located right opposite to the immigration counters that deal with regular visas.
BTW, Aircel India has a tie up with Malaysian MAXIS cellphone service provider. So, you are automatically on roaming as you turn ON your cell phone in KL.
[Update 3rd May 2009]
LCCT offers safety lockers at the cost of MYR 10 for small luggage and MYR 20 for medium sized luggage. It is located nearby the entrance of LCCT Domestic Arrivals door. If you find it expensive to leave your luggage for a longer duration of time, then I would recommend you to take a shuttle bus to KL Central and find one of the Hostels out there that offer locker service for MYR 2 per day. Factor in MYR 14 and MYR 2 for the roundabout shuttle ride and KL metro transit, respectively.