No. Even if your laptop has something like an MXM module that can be swapped out you would also need to upgrade the cooling for a more power hungry card. Generally though for most laptops replacing the GPU means taking the entire thing apart and replacing the motherboard & cooling assembly.
From what I believe, most Asus laptops use MXM III Type B (As seen from the G73's 5870M). The GTS 360M used to be interchangeable with the GTX 260M, as most Asus (such as G73 series) models look identical except for the graphics card. The laptop should support it via motherboard. The only problem I would see is the cooling solution, which may not be enough. If the cooling solution is the same, then the motherboard will recognize it and it will run fine.
Oh, and the GTX 260M and GTS 360M both are only available for MXM III Type B. DO NOT attempt to upgrade to 5870M/460M, as your motherboard will probably not support it.
That vast majority are not while a few are and those that are usually do not come cheap. It is the weak link for many laptops. For gaming on a laptop chose your games and settings accordingly and if you are getting into more demanding games then it is time that you build your self a decent rig.