Laptop question

I have a Toshiba Satellite A15-S129. It has a nice quick processor, but was shackled with an albatross (Intel Extreme Graphics). I've been looking at Geforce FX cards on ebay. I noticed that some of these auctions list what laptops these cards are compatible with. My question is this: Can I buy the geforce FX 5200 GO I just looked at and expect to be able to put it into my laptop? Is it a space issue? Is it dependant on whether or not there is some sort of laptop-esque AGP slot?

I've built several desktops, but have never had a laptop apart so I'm hoping that the laptop experts out there will give me some pointers on upgrading. Also will a 5200 GO w/ 32 MB ram be able to run SL? I'd buy better but price is a concern....

Thanks in advance,

Vince

And find out if their laptops are able to be upgraded, I know certain dells can... as well as the infamous Alienware laptops *drolls* sorry I'm not up to date with toshibas

Thanks for the advice Christian! I assumed that they could be upgraded since desk tops can, but the Toshiba Satellite has the Intel Extreme graphics built in with no ability to upgrade to a real video card.