Austin, Texas--South Congress Avenue, what is there to do? Any suggestions?

I'm wanting to take my fiance on a day trip to Austin tomorrow--specifically South Congress Avenue. Does anyone have any suggestions of where to start or recommendations of places to hit up? I'm not even sure where we should park!
Vespaio and South Congress Cafe are both great places to eat (there's also Homeslice Pizza, Magnolia Cafe, Guero's, Jo's coffee, Amy's ice cream, a trailer that sells cupcakes, and a candy shop with a real soda fountain from what I hear, etc, etc). The Continental Club is pretty legendary and has lots of great live music at night. I'd probably recommend driving down S. Congress, turning onto Elizabeth (or something else central) and then parking on one of the side streets back there (parking shouldn't be hard). There's tons of shops everywhere, up and down congress, and also down some of the side streets on the West side of Congress Ave. Everything is in walkable distance. Magnolia cafe is probably the furthest south you want, and Black Mail is probably the furthest North (if you reach condos and starbucks, you're too far north!).
If South Congress gets boring, there's also South First!