Here’s my annual list of tips, updated for 2012.

That’s one full conference room. Get to your session early to get a seat. Popular sessions fill up quickly, and once they do, you aren’t allowed in. One more reason to plan your schedule in advance.

1. Power equipment: Get yourself a travel power strip, and/or auxiliary battery for your laptop. Being able to  take notes, follow the twitter stream, or research sessions for 10 hours a day is a stretch for almost any laptop or phone. I own and love the Monster Outlets to Go travel power strip, with built-in USB port. It packs down small, and let’s you walk up and use any outlet, even one already occupied.
   
2. Plan out your schedule. There are thousands of sessions you can attend – usually from 40 to 60 during any given timeslot. Which are the ones that are most interesting and applicable to you? Although you should choose primarily based on interest and applicability, all other things being equal it is usually a good bet that speakers in larger rooms are better speakers than speakers in smaller rooms. So get familiar with the map of SXSW, and figure out which rooms are which. Also, it’s not a given that you can make it to any given talk from any other given talk in the allotted time, and still get there with a place to sit. So look at the overall map of all the hotels, and figure out what you can make.
3. Choose your backup talks: For a given time slot, you might have a favorite talk you want to attend. Maybe it will be awful, or maybe it’ll be full and you can’t get in, or maybe it will be cancelled. With SXSW Interactive spread out across many blocks and different buildings and different floors, it’s not possible to get from any given room to another quickly. So once you know your preferred talk for a given timeslot, pick out a backup talk that is nearby.
4. Wean yourself off coffee: Depending on just how hardcore you are, you may want to consider weaning yourself off coffee, or at least reducing your dependence on it. That way, when you get to Austin, you can restart your caffeine habit, and enjoy the full stimulating effects of it. (I wean myself down to one cup per day ahead of time, then plan to enjoy 3 or more cups per day there.)
5. Holy Basil: Like to drink? I’m really fond of Holy Basil, which is a natural hangover remedy. I’ve found it to be highly effective. (I’m not a doctor, this has not been evaluated by the FDA, etc, etc. Be smart.)
6. Business Cards: It’s surprising for such an online environment, but business cards are still pretty popular. If networking is important to you, bring some. Make them simple. Name, email, phone, twitter handle.

At the Start of Each Day

Don’t sit in the back. Go ahead, find a seat up front! Make friends with the person sitting next to you.

1. Be in the moment: Don’t go to a session and then check out and read email, surf the web, or do work. SXSW is precious. Make the most of your time by being totally immersed in what is going on. 
2. Recharge: Look for outlets in hallways, restaurants, outside, anywhere, and use them when you find them. 
3. Conserve power: If you are taking notes on your computer or blogging the sessions, you may want to turn off wifi on your laptop to save power (and to keep your focus on the session, so you don’t start random web surfing.) I usually use my smartphone to follow twitter and email so I’m still connected.
4. Follow the #SXSWi tag on twitter: You want to follow #SXSWi so that if another session is excellent and your session kind of sucks, then you can make the switch quickly. (or conversely find out if a room is already packed and can’t fit any more.)
5. Follow the twitter tag for whatever session you are in: There will be a back channel of conversation about the session you are in that is almost as valuable as the primary speakers. SXSW is full of experts, both presenting and in the crowd, and you want to tap into all of that wisdom. This doesn’t violate tip #1, because you are not being distracted by something different, but rather tapping into more of what you are already there for.
6. Talk to the people around you: SXSWi is a social place. The people around you are likely to be very experienced, smart, interesting people. Start up conversations, make dinner plans with strangers, and keep going until 2am. The wisdom of the crowd is not just an abstract thing at SXSW – it is manifest in the people all around you. Talk to them.
7. Attend my session: Wall-E or Terminator: Predicting the future of Artificial Intelligence, with author Daniel H. Wilson and scientist Chris Robson – Tuesday at 9:30am.