Pro Tip for travelers and conference attendees: Always bring a small power strip with you. Even if the only outlet at the airport is already in use, you can usually ask that person to swap their charger out and share your strip instead.
Additional perk: Even if you only have a single device, you make a lot of friends by sharing your free outlets with them.
Lastly, when traveling to places that need a power converter, you only need one converter for the entire bar!
I should upgrade to one of these, with USB built in: http://www.amazon.com/Outlets-To-Power-Strip-USB/dp/B0018MEBNG