small office speakers

Looking for some small speakers for my office (11x13).
Want the best sound possible, but must be smaller than bookshelf. Any ideas?
Are they going to be placed in a bookshelf? What typical volume will be used? Background music primarily, or do you jam while working? What are you going to listen to?
I bought a pair of small Mission and am very happy. I think Audio Advisor sells them.

You've got some good choices available, but I'll share what I am using in my office: a pair of Krix Equinoxes that I bought for $300 (used) on Audiogon. I think they're an excellent small speaker which meet your criteria for a true bookshelf unit. Some other choices might include the PSB Mini's, the Dahlias (Dick Olsher of Stereophile mag fame designed these), etc.
I use a pair of Paradign Active 20's. These have built amps and the sound is incredible for a small room. They usually can be bought when they are avaliable on Audiogon for 900 to 1000. Not a bad price when you consider you don't need any cables or and amp.
Hard to find, but a pair of Linn Kan II speakers is very nice for the office - very small, made to be very close to a wall, extremely musical. They have to be found used and are likely to be $350-500, but if you can find some, they fit the bill perfectly. -Kirk