Booking opened just a few minutes ago for Juan Diego Florez's Royal Festival Hall recital on 20 January 2011, and already all the best tickets are gone (held back for the organiser, Rosenblatt Recitals, I wonder?). Nice to see Juan Diego doesn't forget the people who gave him an early break, by the way, and also that there are loads of cheap £6 seats in the choir, if you don't mind looking at the back of his head all night.
There are plenty of seats left at sides and rear at the moment, though I don't expect they'll last for long, so get your skates on.
Also just opened for booking is Simon Keenlyside at the highly atmospheric (if acoustically dodgy) Temple Church on 22 October 2010. While you're at it, take a look at Temple Music's other events, which include recitals by Nathan Vale and Mark Padmore, and Monteverdi's Vespers by the Sixteen.