I agree with packrat. Your Q score is definitely too low for top schools and if you want to be competitive you should bring it up to 160+. Keep in mind that it is more than just a measure of your "intelligence" (I should say here that I do not believe that it actually measures intelligence or anything that reflects your potential as a researcher). A high score on the GRE can also be a sign of determination - something that is very important for grad school. I had to take the GRE five times (and spend more than $1000 on books, test fees etc.) to get mediocre+ scores (V:163, Q161).
GRE score don't get you in, but they can keep you out. Feel free to PM me and I'll suggest some prep books and online resources.