Thanks to Gravity (2006) is, to put it mildly, one of the less documented movies where Austin was in.
He plays a character named Alex Ford and is the leader of a debate team (not unlike the part he played at the beginning of TDAT).

There is hardly anything about this movie on the internet. 
The official site of the movie no longer exists. The trailer is nowhere to be found.

A review of the movie by ROBERT KOEHLER

A Voyage Entertainment presentation. Produced by Amy Greenspun, Gina Philips. Directed, written by Jessica Kavana-Dornbusch.
 
With: Gina Philips, Adam Rodriquez, Rachel Miner, Sean Astin, Bryan Greenberg, Chris Mulkey, Azura Skye, Austin Nichols, Joaquim de Almeida, Eve Gordon, Shirley Knight, Sendhil Ramamurthy.
 
A smart, attractive Jewish Latina lands on her feet in the heated twin atmospheres of college debate teams and college guys in the thinly realized "Thanks to Gravity." Dulled by paint-by-numbers dramatics and first-person voiceover narration galore, pic should have a you-go-girl peppiness but amounts instead to a tepid sentimental education. Multicultural appeal looks on paper to be a dream for Jewish and Latino fests, but undemanding item is best geared for gal-oriented cablers. 

Synopsis

Acing the guys in high school debate, Miami-born Jordan (aptly cast Gina Philips) attracts the attention of the Harvard debate team and is awarded a scholarship. Things turn bad when Jordan is raped by a debate opponent, and later is led astray by one cute guy (Brian Greenberg) and pursued by another (Adam Rodriquez), who's at least acceptable to her parents because he's Jewish and Cuban. By act three, Jordan screws her head back on and reaches the national finals, where she faces off with none other than the scumbag rapist. Distingushed thesps Shirley Knight (as Jordan's loving grandmom) and Joaquim de Almeida (as stern but loving dad) are saddled with rote roles.

Spoiler

Did you read the synopsis.
Now who do you think the ‘scumbag rapist’ is?

Another review Polly staffle

An interview with Gina Philips - A glimpse of Austin can be seen at the very beginning of the clip

Thanks to Gravity Q & A - pics at Austin Media