Also I forgot to mention, you should really take one thing into effect, The GMAT is going to change in June 2012. Not a complete overhaul, but a new section will be replacing one of the AWA. See my excerpt from one of my posts in a seperate topic:
"The test will be changing with the addition of a new section called 'Integrated Reasoning'. The IR section will be replacing one of the Anlytical Writing sections. At the time of publication there was no details on how it would be scored but the books suggests that Verbal and Quant will be weighed within the 200-800 range, the one AWA will be marked 0-6.0, and the IR could be weighted separately. According to the book as well, the questions could be based on some innovative past experimental questions to show up on the GMAT, such as charts, graphs, spreadsheets, and possibly even audio."
So make sure you keep this in mind!