I don't mind contemporary fantasy, but I do get irritated when a High Fantasy world is mixed with modernity. Like, if they discovered an iPhone in Mordor, I'd be done. But Anne Rice, Jonathan Stroud, and JKR have all done fantasy in 'contemporary' settings and it doesn't bother me because these ideas were all disclosed up-front (I guess you could say, they have stayed true to the pact they have made with the reader).