Most if not all 403(b) plans will not allow a withdrawal while you are currently employed. See page 12 of IRS Publication 571, link below.
If your plan allows for the distributions, you can roll the amounts into an IRA tax free.
As I stated in my original post, if it is rolled into an IRA there will be no tax.
To avoid any potential problems you should use a direct transfer from the 403(b) plan to the new IRA. If you choose to take the withdrawal personally and then deposit it into a new IRA, the transaction must be completed within 60 days of the distribution.
You should also elect to not have any tax withheld or you will not roll over the full amount. The tax withheld will be classified as a premature distribution. This portion will be taxable at your incremental tax rate and will also be subject to a 10% penalty tax for early withdrawal.
Much of this is also covered in Publication 571.