This sounds very similar to the Burger King Xbox Kinect giveaway about a year ago, so we can only hope there's some kind of free code method like that one had.
Here is the description from the Playstation blog on the 3 ways to win:
UNLOCK THE BOX: Beginning January 26th, Taco Bell’s specially marked $5 Buck Box – which includes a Cheesy Gordita Crunch, Crunchy Taco, Burrito Supreme and medium fountain drink – will also provide a code that can be entered online for an instant chance to “unlock” and win a PS Vita.
BATTLE: Download Taco Bell’s new mobile app to check out the exclusively designed Reality Fighters Dojo game where you can “battle” your friends to win a PS Vita.
BOAST: Taco Bell’s online contest will encourage you to submit a photo or video “boasting” about what you’re willing to do for a PS Vita. Submissions will then go into an online gallery where you and your peers can vote for the winners – it could be you!
I'll convert this over to wiki mode if we start finding free codes.
Contest is now live:
Main Site: http://unlock.tacobell.com/
iOS App - http://itunes.apple.....7361?ls=1&mt=8
Android App - https://market.andro....tacobell&hl=en
There doesn't appear to be any freebies (unless you mail for free codes in March) or any ways to enhance your odds besides collecting votes on Boast pictures.
Update: Since this turned into primarily a referral thread, I've wikified it so you guys can duke it out. Have at it.
Edited by FadeToOne, 08 February 2012 - 03:21 PM.