Unfortunately, your options are currently pretty limited if you're looking to retain laptop portability.
You can read up a lot about the debate between positive and negative air pressure cooling setups. All laptops I've opened up have fans that pulls the hot air out, creating a negative air pressure system.
Cooling pads, for the most part, are designed to force air through the bottom vents in the laptop, effectively converting it to a positive air pressure system (assuming more air is pushed into the laptop than is pulled out). I'd follow Stonerboy's suggestions if you're looking to purchase another one.
Some argue that because laptops were designed with negative air pressure cooling in mind, the effectiveness of cooling pads is limited. For those people, other cooling accessories were created to attach to the existing exhaust vent and aid the existing exhaust fan in drawing the hot air out. Otherwise, people have modified laptops with positive air pressure cooling in mind: enlarging bottom intake vents around cpu/gpu, adding miniture heatsinks to increase surface area for convection, and going with a single fan cooling pad.
I'd have to agree with wevsspot on all points.
Personally, I bought a used Asus G51VX with an overheating GPU, despite replacing the thermal pads (PO tried using a lot of thermal paste with no positive result). For experimental purposes, I used a Scythe Ultra-Kaze 120mm fan to act as an accessory fan. Tried a few configurations, but these two stick out:
1) Coolest CPU temperatures with the bottom cover off and the fan blowing directly onto the motherboard
2) Coolest GPU temperatures with the bottom cover off and the fan blowing directly into the exhaust vent (against the exhaust fan)
Removing the bottom cover essentially creates an open air system. By blowing air onto the motherboard, you're simultaneously pushing the hot air away and supplying cool air.
The second point had to do with the design of the cooling system. The CPU and GPU both had their own heat pipes, which each had their own set of heatsinks. The CPU heatsink was closest to the exhaust fan, effectively supplying the GPU heatsink with hot air. Supplying the GPU heatsink with fresh cool air took the temps down a lot, at the expense of effectively forcing hot air into the system.
Turns out that the optimum (most effective with least amount of effort) cooling modification for my particular laptop was to place an on/off switch on the PWM fan control wire. Apparently, the fan wasn't ever on at lower temperatures, and never ran at 100% even when the GPU was overheating. By using a switch, I have the ability to allow the motherboard to control the fan during normal, low intensity tasks, and have the fan on at full blast for more intensive tasks. No software fan controller worked for this laptop at the time I was looking.
In the end, I guess, it's laptop-dependent. Best of luck figuring out what works best for yours.
Edited by Kiro, 25 September 2013 - 11:18 AM.