Going to SXSW is a great experience for photographers. You will probably photograph more shows in a week than you do in several months in your hometown and access is pretty open on the smaller stages. I loved my visit last year and wanted to share a few practical things I learned.
The SXSW photographer survival kit
Reusable Water Bottle -
Austin is hot and dry and you will be sweating a lot running around town with a camera bag. Fortunately or unfortunately depending on how you look at it, there is more free beer given away at SXSW than free bottled water. However, most venues set up coolers with free tap water that you can refill a water bottle with. Do this every chance you get. I attached mine to my camera bag with a carbineer.
A nice little travel pack of these fits discreetly into a camera bag. When you're in the war zone and need to wipe off grease from the visits to the ubiquitous street sausage carts or Death Metal pizza, these will come in very handy. Will freshen you up better than cheap napkins and keep the grease off your camera. Also good for fending off crotch rot and for any bathroom or lack-there-of emergencies.
Sweat/Beer Towel -
Great for mopping your brow in the sweaty Austin heat and for sopping up spilled/thrown/sprayed beer off your camera. Take one with you from the hotel room in the morning or pack a few from home.
Roll-on Sunblock -
I like this little Neutrogena SPF 30 Sunblock stick. It doesn't take up any space in the bag and won't leak. Stands up to sweat and its not greasy or slippery.
Mini Flash Light -
Either a mini mag-lite or LED keychain will help you find stuff at the bottom of your camera bag in a dark club. Last year I stayed in an Airstream trailer in a local Austinite's back yard. That flashlight came in mighty handy finding my way and getting the key in the door.
Between the sun, the beer, the sweat, the noise, the slam dancing, the walking and the standing you are going to need it.
Notebook + Pens -
There is so much going on that it helps to write out a plan for the day. I used a moleskine reporter notebook to write out my schedule but if you are more tech savvy there are a bunch of iPhone apps to help with scheduling (although service may be spotty). Check the local newspapers as they have comprehensive schedules listed as well.
Backpack Straps or Backpack photo bag-
I use the Think-Tank photo Urban Disguise 60 as my main carry around bag. They have a nifty shoulder harness accessory that hooks onto 2 D rings and the handles of the bag to give you a back pack strap. This greatly reduced fatigue throughout the day. Also think carefully about what you really need and pack as light as possible without forgetting the essentials.
Energy Bars -
There is not a lot of time to stop and eat and your choices on the main strip are basically pizza and grilled meats of varying quality. A few good energy bars stashed away will help you get through an energy crash when stopping to eat means missing a performance. Austin is the hometown of Whole Foods so you are in luck, there is a big one not too far from the action.
Good supportive and comfortable shoes, light, breathable clothing and extra earplugs-
No explanation needed.
Good Luck! If you have any more suggestions, leave 'em in the comments.