The grandpappy of all LCCs, Southwest Airlines in the US (and arguably the best airline in the world) have no seat allocation and never will. They use an A, B and C system. There aircraft is broken into 3 boarding groups (all equal) so if you get to the airport and check-in early you get a boarding pass with an A on it. You get there on time you get a boarding pass with a B on it. You get there late you get a boarding pass with a C on it. When it comes time to board there are 3 queues at the gate, funnily enough A, B and C.
The 'A' s board first and get the pick of the seats, Bs next and the Cs get what I like to call using harness racing parlance, the death seats (not great in aviation terms though!), or middle seats.
While it does not eliminate the possibility of a stampede, the system certainly reduces the rush and actively encourages passengers to CHECK IN EARLY. For the airline, it almost illiminates the the possibility of passengers damaging the on time departure performance. (Almost!)
It is a great system and works extremely well, if Jetstar were going to use a drafting race to board passengers they could do worse than to have a look at SWAs system