Start to wind down your prep. Maybe take one more GMAT practice test, but as you get closer to your actual test date do less and less.
Think about putting together some flashcards of key concepts (if you haven't done so already). Review those cards a couple times a day to stay fresh on the material.
The day before your test, don't do anything! Go exercise, go to a movie, go to a spa--do something besides studying. People tend to forget that the GMAT is a physical activity, and you're going to need to be rested.
Finally, on the day of the test eat a protein-rich meal. I recommend peanut butter and jelly--it keeps you full for a long time.
Be confident and kick some butt! You're in the home stretch!
Look forward to reading your 'I just Beat The GMAT' debrief.
