I saw one idea on myleague.com(one of the biggest online league gaming sites).. what they do is they give people a rating only after 20 games.. till 20 games players are all provisional.. they do not get a rating calculated.. after 20 games they get the actual rating.. what it does is it makes smurfers wait a long time before they can play at their correct level.. also people can chose not to play with provisional players.. or they can play in their own provisional lobby.. though this will not stop smurfing completely but it will make it time consuming for someone to create a smurf account and get to anywhere decent..