My entry for the MIX09 10k Challenge was recently accepted.  You can view my entry at this page:

http://2009.visitmix.com/MIXtify/TenKDisplay.aspx?SubmissionID=0079

You can give the app a spin on the entry page, or down below.  If you like it, don't forget to give it a vote on the entry page!

The app is named "PiCheat".  It is a simple tool to help visualize basic right-triangle trigonomic computations.  As you move your mouse around the circle, the mouse forms angles from the x-axis.  The angles in degrees and radians are displayed, along with sin, cosine, and tangent values for the angles.  The x and y values of the right triangle are also shown for the angle, and you can change the radius of the circle which will reflect new x and y values as you move around.  You could do so much more with this app beyond 10k of code, but I obviously had to stop once I reached the source code limit.

After the contest is over, I may publish the source code.  And I must say, the source code is ugly - but on purpose.  I named my variables with very short, cryptic names to conserve space and I can barely read the code.  If I take what the Visual Studio formatting gives me, my app is over the 10k limit, but after trimming down all unnecessary white space it goes down to about 8k.  No line breaks anywhere!