I agree that it can be difficult sometimes. My company pays for my cabs if I work late, so I end up taking a cab about 2/3 times per week from Bond Street. I get turned down about one time out of ten and sometimes have to deal with an annoyed cabbie even if they do agree - i had one nutcase complain during the entire 20 minute ride about how much he hated that he had to go all the way to ED (mostly under his breath). Charming! But I find that it's easier if I say Lordship Lane instead of just ED and I always ask them to go via Vauxhall Bridge - going all the way over to Westminster Bridge and then down the Walworth Road always adds at least 10 minutes and ?5 to the fare(and is completely aggravating!).