My 60gb ps3 is freezing?

May be...

i had my ps3 almost for 2 years[got it in february 07]. now it keeps freezing every time i press the ps button during a game. at first it just froze at the xmb icons loading. now the xmb wont even come up and its just has the spinning loading thing... Also when i quit the game,the screen stays black. what should i do? reformat the hard drive or call sony?

First reformat then if that doesn't work. You are gonna have to pay sony 150 dollars to fix it since you aren't covered by the warranty anymore.