In Austin, definitely get some Jester King. Great local farmhouse brewery. :rockin: And I like it how they are stickin it to the TABC!
Live Oak is another great local brew -- BeerAdvocate rates their Hefe in the top 100 - it's really that good.
Real Ale from Blanco, TX is another excellent brewery with plenty of distribution around the area.
Ditto on the (512) Pecan Porter - great stuff
Also venture out to some of the local beer and brewpubs; Draught House, Black Star Coop, The Dig Pub, Whip In, Billy's on Burnet, Uncle Billy's Brew and Cue, North x Northwest, and the Gingerman. These all tailor to good brews and/or in house brewing.
If you do get a chance to visit Black Star Coop (the only beer coop in the States I believe), definitely try some of their own beers. But they also do have the Rahr Bourbon Aged Winter Warmer on tap -- yummy!