My favourite thing at the moment is augmented reality, so I'm completely in love with the video clip project for Sydney band Lost Valentinos song Nightmoves.
While it's a far cry from being my favourite song, the band has a dedicated site where you can print out five separate markers - one for each member of the band - and then use your computers webcam to watch the band spring to life and sing their song. You can then record a video of you doing that and share the clip with other fans on the same site.
Because the whole thing just works off printed markers, you can have as many band members as you'd like as well. Some of the clips already uploaded include sitting them in front of the Opera House and standing on someone's head.
You can check out the site for the band - as well as print off your own markers - here.