Laptop to play flight simulator X. Any suggestion?

It more depends on how much you are willing to spend. There are a few $500 laptops that will do the trick. I prefer toshibas myself.

Thanks.
I can spend up to $600 or maybe $700. Should I look for some specific graphic card?

I would head on over to a few of the many active fsx / flightsimulator forums and post there. I have fsx and gained alot of help this way.

Strangely as it might seem, the gfx card doesn't have as great an impact as you might think for this game....however, these folk will better advise on minimum gfx horsepower for a laptop i.e. they'll tell you what mobile gfx cards you can select from, then, you simply make sure your laptop has one. CPU & memory-wise, the vast majority of new laptops available should be fine - though ask for confirmation here also. You might want to check also out the REX (realenvironmentextreme) forums.......damn good add-on also!