Make Your Own TapTap Song

Hey, what do you guys think about making an app for your computer/online where you can import a song (could be illegal but what do I know) and go through the song second by second and place dots/things you hold down for a while and eventually import it onto your iPhone or iPod touch like how you can make custom levels for Cube Runner online and it gives you a URL to put into Cube Runner. Also like Labyrinth