Carry an extra battery for your phone if you're attending a conference or will be using it for an extended period of time. I can honestly say that this little piece of advice has saved me from embarrassing moments when demoing applications to people and the phone's battery is dead - not cool.

When you're at work or home, being able to plug your phone in to charge is second nature. However if you're walking around a show floor or in meetings you'll run into two problems: finding a power outlet and finding time to charge your phone.