I just got back from my travels, and saw this lovely Printstik in a magazine.  It’s now at the top of my wish list, it’s a portable printer that only ways, 1.5 lbs (that’s lighter than my travel hairdryer!).  I also just read about the HP iPrint Photo application, which is also great and allows you to print your photos on Wi-Fi enabled ink-jet printers from HP within the range of your wireless network.