I did not attempt to beat the GMAT, I did not study...although I had originally planned to do so. I did however take the GMAT prep tests offered on MBA.com. As is indicated in this forum, they are a pretty good assessment of how you will ultimately score on the test. I scored the following;

Prep test 1: 630
Prep test 2: 600
Actual GMAT: 610

I am happy with my score, I am a little disappointed that I didn't have more time and really work on the quantitative area (I'm very weak here), but it is definitely enough to get me in to the university.

My only note is on clock watching. I have no idea how I will score on the written portion. I looked at the clock and had 6 minutes, I decided to add an actual experience to the analysis of an argument (1st section) and before I knew it the clock ran out and I was literally typing in the middle of a paragraph. There is no flashing light or obvious sign to get your attention when you are running out of time. I excel in writing but will probably get a considerably lower score because I did not watch the clock so be aware of this as you sit down to take the test. If you goof on the first section it also makes you needlessly paranoid throughout the rest so don't let it happen to you:)

Good luck all,
Dana