Hey WiiJ, won't you play that song?

I'm not sure if he is the first one to do this, but he is the first that I found. Mashup DJ ! (pronounced Shift-1) learned about Wiimote hacking and figured he would experiment with the Wiimote and his DJ setup. Here are a couple of videos from his website djWiij.

Beatmatching Demo
 
Scratching Demo