As you say, Capfka, LA (or alternatively, San Francisco) is fine for flights from the UK (and the least bad for Antipodeans) although it does seem to cost nearly as much for USn's to get there from the East Coast or Mid West as it does for me to get there from Edinburgh! The main problem with the springtime is that for those tied to educational establishments that do not allow vacations within termtime, the Easter holiday and spring break tend not to match up.
Looking at the prices on E-bookers.com from the UK, New York, Boston, Denver, Miami and Orlando all offer cheap flights. Examples at today's date: New York £175, Boston £179, Washington £184, Chicago £214, Denver £237, Miami £218, Orlando £261, Los Angeles £215, San Francisco £214, Toronto £431, Montreal £342, Vancouver £514, Quebec £448.
I suppose that much depends on someone volunteering to organise the next event.
