Austin will always feel like a second home to me in my heart of hearts.
Go to Freebird's and have a burrito. This ain't no frozen flour-encrusted morsel, it's a meal in itself and absolutely delicious! You might also check out Bass Emporium while you're there. Last time I was in, they had several nice basses including Elrick, Sadowsky, Modulus, and I think a Stingray or two. Sixth street should be seen at least once, I suppose. Oh yes, for some killer Tex-Mex food and atmosphere, go to any of the three Chuy's restaurants according to where you are in Austin. Since you're going to a conference you'll likely be staying in a hotel close to I-35...so the Barton Springs Road location will probably be closest (also the best, IMO).