That Wii hacking community sure is a musical bunch. First came word of a drumming hack that turned Wii remotes into virtual drumsticks. Now comes another hack that turns a pair of remotes into a sort of air guitar.
As described on the WiiLi.org discussion board and demonstrated in the below video, the simple PC program uses one remote to detect strumming and another to determine which frets are being held. Chords and arpeggios are also possible with some complex button combinations.
While the setup is a little less than intuitive, this proof of concept should be all an enterprising hacker needs to set up a fully functioning air guitar game using the remote. Now all we need is a wii remote-controlled keyboard and bass to bring our dreams of a real (virtual) air band to fruition.