I recently read the YA novelette (?) D.A. by Connie Willis, published in 2007. It was quite good. It features Ms. Willis' fabulous voice--which I really enjoy. Her voice is particularly suited for the young female protagonist in this work; thus, characterization is excellent. The plot is also good: the protagonist is basically forced to become a space cadet against her will and, suffice to say, antics ensue. You will have to read it for yourself to find out what the mysterious title refers to. :)
If I have criticism of this work it's that it is too short. It is also quite difficult to get a hold of. If you can find it and afford it: enjoy!