At SXSW, I attended the Groupon brunch at the Iron Cactus. Some of the attendees, myself included, received a Griffin TuneJuice portable iPhone charger as gifts for coming to the brunch.
Last week at Obliterati, I was able to acquire a Powermat 2X in the gift bag. This device is not only a universal charger, but it is able to do it with minimal wires and clutter, allowing the user to do it with a minimal footprint.