This is what I plan on spending the rest of the year doing (taken from the Final Year Project Page):
This project will design and implement a musical instrument tuner for mobile phones using J2ME. The first phase of the project will test and calibrate the microphone of the mobile phone to ensure sufficient signal quality for analysing the pitch of a note. The second project phase will implement the tuner ensuring that it can recognise the correct pitches and display them to the user in an easy to understand manner. The final project phase will evaluate the implementation by comparison to commercially available (low-cost) instrument tuner models.
Lunacy to attempt? Probably. Will it work with current technology? Probably not. Are you mental? Possibly...