KickSat: open source spacecraft project
I was wondering if it really was a good idea to spread so many little things in orbit, and was subsequently very happy to read this in the paper linked by jimsojim:<p><pre><code>    Due to their extremely low ballistic coefficient, 
    the Sprites are Expected to remain in orbit for only 
    a few days before reentering and burning up in the 
    atmosphere, alleviating debris concerns.</code></pre>