"SatoshiDICE" notifies gambling addicts of losing bets by sending them a transaction containing 1 satoshi back to their original address. A regular transaction fee is also included in this transaction. The problem is that this produces an unspendable and unprunable output.
u can spend them, wait some time (so they arent "new coins" anymore, dunno how many blocks that would be) and send them even with 0 fees trough the raw tx API.