We place such a premium on USB ports because, let's face it, just about every digital gadget plugs into one these days, many of which are capable of recharging themselves through your PC. But instead of keeping track of both a USB cable and a power plug, why not just convert a spare in-wall outlet or two into a USB outlet? In the words of the Guinness brewmasters, "Brilliant!"
All this mod takes is about $10 and a half-hour of your time, with a little bit of courage and a whole lot of safety precautions highly recommended. The relatively simple mod involves taking a pair of cheap USB chargers easily obtainable for a few bucks on eBay and stripping off the extra casing. Mod the faceplate, wire it up, and you're good to go!
Image Credit: Instructables