I'm a CS, and in lieu of a bachelor thesis, we did a senior programming project involving neural networks to analyze stock market trends. We did well on it, but not well enough that we were able to put it to use to make a fortune.

My Masters project, however, was more interesting (to me, anyway) and involved creating, imagine this, a "Smart Music Player." I don't think you have to go far to think of what inspired me to pitch that to my team. Unfortunately, I was one of two software developers on the project, so while I think we did a good job of the planning, requirements, analysis, and early design, we never got to do any implementation (which we weren't necessarily expected to, since the scope of our project was so wide.)

Not sure if the format of this project is anything like what you'll be expected to do for your thesis, but if you want something to get your mind going, take a look.

http://www.tonyc.org/files/SmartMusicPlayer.pdf