I've really been enjoying Eunny Jang's Endpaper Mitts
Following the votes of most of you, I started with the brown and rose. (For those of you who preferred the brown and blue, have no fear. I think they may be up next in the hopper.)
I especially enjoyed learning the Italian tubular cast-on. Eunny suggests it and links to this wonderful tutorial. Although at first I had trouble learning the technique and counting the stitches at the same time, once I got used to it, the cast-on felt like swimming, or dancing. As a relatively ambidextrous person, I love anything that really allows both hands to get in on the action. The rhythmic back and forth is quite soothing.
If you try this cast-on, don't forget to pull out the extra yarn (as described in the tutorial) in order to get the most aesthetically pleasing and elastic edge.