My MPB keeps shuting down!

So, my 3 month old Macbook Pro is behaving worse than my 5 year old $500 desktop pc. As of the last week, the screen gets dark from top to bottom and it says I need to shut my computer down, and the only way is to use the power button. Admittedly, I occasionally peruse some porn, so I'm wondering if that is part of the problem. The internet has been super-slow lately as well, and it seems like the only way to fix it is to turn airport off and on. I also feel like the timing of the shut-down problem coincides with me downloading firefox, but I've never heard of anyone with similar problems. I've got applecare and plan on taking it to the nearest store (50 mi away). What can I do in the meantime, is there a way to just wipe this thing?

See this thread.

Go to the store armed at least knowing whether or not it is the airport card.