According to the IRS, you can deduct your moving expenses if you meet these three requirements:

A Quick Summary of Requirements:

1. Your move is closely related to the start of work. Are you moving for work?
2. You meet the distance test. Is it more than 50 miles from your current work?
3. You meet the time test. Are you starting within a reasonable time period?

Those are the basics.
 
But you better check out the details from the IRS website right here:

http://www.irs.gov/publications/p521/index.html