The best place to ask this question is your local tag office. If you transfer title a week or even a day before your birthday, the next renewal date will still be the date of your birthday. If Ad Valorem taxes for the year you transferred the title in were paid, you will pay the tagging fee and title transfer fee for that year, then on your birthday pay Ad Valorem tax and the renewal tag fee. Often if you are right before your birthday they will let you go ahead and pay all the fees for the next year right then and simply give you a tag that is good until the birthday AFTER your coming birthday (So, say, for a year and two weeks or so, if you did it right now it would be a 2010 renewal rather than a 2009 renewal) and they will do this because it saves them time and effort, not because it will save you money. I've never been able to get out of paying tagging and renewal fees, regardless of when I transferred title. If you can get away with it, good luck.

Don't forget that you need a valid emission (Meaning it is a pass performed less than 365 days before the date you renew) for all vehicles that are not somehow otherwise exempted, meaning less than 8500gvwr or 25 years old ('84 this year).