For this reason, I never bring a laptop computer with me anymore. I find them too bulky and distracting in the sessions. I use my Windows Mobile 6 device to take quick notes that I email to myself and carry a small pad of paper for more extensive notes, if necessary. Bring a few USB thumb drives to download presentations onto from the kiosks. You'll get the PPTs on DVD serveral weeks (months?) after TechEd, but it's better to get that content while you're there.
If you need to bring a laptop, CommNet does a pretty good job of setting up access points all throughout the venue. You will notice flat panel displays in various areas and levels of the conference center that show you realtime coverage maps and signal strength. The biggest problem I've heard is that the APs don't provide good coverage inside the session areas. If you need Internet access in a session, sit closer to the back of the room (closer to the APs). Better yet, use one of the CommNet computers outside so you don't distract others around you - you're probably not paying attention to the session anyway.
I typically carry my empty TechEd backpack. The best was the one from San Diego, which I use every year, the worst was the infamous TechEd "man purse" from Boston, 2006. The only thing I carry in it is a pen, pad of paper and my mobile device. Magically it's filled with t-shirts, books, pens and other swag when I return to my hotel room at the end of the day. Don't bother bringing food or drinks with you to the conference center. There will always be food and drinks available there throughout the day. I'll blog about the food in a future post.
I usually come to TechEd with two suitcases, one inside the other. That way I can load the empty suitcase with my body weight in t-shirts and swag for my colleagues that couldn't attend.