Wow. This is painfully obvious. I don't know if I would call it a hack though. More of a workaround. I am quite sure Microsoft will come with a workaround of their own soon too. Anyhow, here is a way to get around the 3 play song sharing restriction.

tag 

This is a bit of forehead slapper if you ask me. We thank the Zune team for ridding the wretched three day play rule, but they left the three play rule and that makes us cringe. Thankfully Zune Scene has figured out how to get around that, but this should only be used for tracks that you produce yourself or tracks from your musician-type friends. *wink* You simply need to change the genre tag for your files to ‘podcast’ and voila. Have fun and enjoy your unlocked tracks.

Source: Crunchgear