I forgot to mention; it happens most often when I'm in town. My character has been trying to do his crafting in town, between crashes.
I just came here to post a thread about this too. My case isn't too severe like AlienSlof's crashing every few minutes though. I get it after a few hours of playing, with a crash report dialog... but something different happened just now. I was just riding my horse then the game froze and then crashed, with the normal os x crash report window, instead of zenmax's.