Breakfast/coffee
Granny's taco truck right off 7th in East Austin. We recommend the Rico!
Civil Goat, where Brian gets coffee every Saturday morning before Cora gets out of bed. Brian likes the Guadalupe location and Cora likes the Manor location. They have great breakfast options, but you will get more bang for your buck at Granny's.
Epicerie for the best kept brunch secret in town! (They don't take reservations.)
Snacking
Antonelli's Cheese Shop in Hyde Park.
Lunch
Homeslice Pizza, Food Heads (fresh sandwiches), Elizabeth Street Cafe (French-Vietnamese), or Uncle Nicky's (counter-service Italian and gelato).
Or Bill's Oyster in downtown for an upscale oyster bar with great seafood offerings.
Dinner/drinks
The Dead Rabbit is an Irish restaurant/bar with a very fun atmosphere that just opened across from the Driskill on Sixth Street. Great food, if you're longing for some of your Irish/UK favorites, and great staff.
Alternatively, Murray's Tavern is an elevated New York style tavern in East Austin.
For finer dining, check out Lenoir (small plates/local ingredients), Pecan Square Cafe (beautiful interior and high-quality food), Peacock (mediterranean), Uchi (sushi), Clark's Oyster Bar, and Dai Due (a meat lover's paradise--more casual than the others).
Dive bars
Nickel City or Donn's Depot.
South Congress
Walking South Congress is probably our favorite way to spend a Saturday afternoon.
Start by going to Homeslice Pizza. Skip the long line that forms outside and go directly inside to order at the counter. Watch them toss the dough as you eat a slice of Margherita (out of this world).
For stores, we recommend checking out Stag for unique men's clothing and Maufrais (next to Allen's Boots) for a personal hat-making experience.
Check out Continental Club for live music and cheap drinks.
And don't skip ice cream at Jeni's! It will be August, after all.
Barton Springs
Enter on the Azie Morton side. $5/pp entrance fee. They don't allow food or alcohol (but you could sneak in a little Antonelli's picnic if you really wanted).
The Greenbelt
Hike and swim! Start at the Violet Crown trail head or at Trail's End--this is a steep decline (and thus, steep incline back up) but perhaps the best water hole is at this trail head!
Indoor Activities
If you're looking to beat the heat, you can't go wrong visiting the Texas Capitol or the Bob Bullock (Texas history) Museum.
Evening
If you arrive in Austin a day or two early, catch jazz at Monk's Jazz Club, or go Texas two-stepping at Broken Spoke, an Austin institution.