Disproportionality in UK electoral system

A neat interactive demonstration from the BBC:
http://news.bbc.co.uk/1/hi/uk_politics/election_2010/8609989.stm

With the three main parties getting equal shares of the votes, Labour very nearly have a majority of the seats. (Though there are clearly some slightly strange assumptions at the limits, because "Other" still get 24 seats if you set their share to 0.0%, and Northern Ireland only explains 18 of them.)

(via http://www.boingboing.net/2010/04/19/lib-dems-soar-in-uk.html)