I took the GMAT (for the 1st time) on December 20th with the goal of scoring a 680+. My MBA applications for the Fall 05 semester were completed at the time.
I received a 630 and almost did not apply at all. I thought about retaking the GMAT and applying for the Fall 06 semester. However, I decided to send in my Fall 05 applications instead before the 2nd round deadline (because the worst thing that could happen is that the MBA admission committees will say no which is the same response I would have gotten if I did not apply at all for the Fall 05 semester).
So I applied to Northwestern (Kellogg), Michigan (Ross), Dartmouth (Tuck), University of Virginia (Darden), Carnegie Mellon (Tepper), and Indiana (Kelley).
I was rejected by Kellogg and Tuck. I was accepted by Kelley & Darden yesterday and Ross today. However I was placed on a waiting list for Tepper.
So my advice to you: Apply to a MBA program even if your GMAT score is not as high as you like!