Forget about getting to London today -- nine flights have been cancelled out of LAX because of the volcanic ash problems in Northern Europe, and many more are likely to be scratched later in the day. It's the same with Paris. Authorities are saying that Heathrow might reopen by early Friday, but the folks who were scheduled to be on cancelled flights might have a hard time finding seats. From the NYT:
The shutdown, among the most sweeping ever ordered in peacetime, forced the cancellation of thousands of flights and left airplanes stranded on the tarmac at some of the world's busiest airports as the rolling cloud -- made up of minute particles of silicate that can severely damage airplane engines -- spread over Britain and toward continental Europe.
You can get flight information through FlightStats.