A tiny printer
I've found out from experience that my big pro printer is not really handy when I want to give small prints to friends. So I bought the tiny Sony DPP-FP55 printer. It can print from a SD memory card, or via USB plugged into a digital camera, or from a Windoze PC. (If you use Mac and want to print pics from your computer, you can copy them to an SD card.)
It's simple to use, and much fun. The prints are like drugstore prints, 10x15 cm, and cheap. And of gorgeous quality.
I snapped the above picture of it. As you can see it's no bigger than a lunch box. The prints are my neighboring houses (which you've seen I use for testing), the recent sunrise picture, and my friends Peter and Ale.
It's the perfect thing when you are photographing people, in a social or a professional context, and you want to give them an instant print. It is almost as fast as a Polaroid photo, and the quality is much better. And of course you have the digital file for much bigger prints later, or for the web.