I save all the numbers of the ladies I've gone to see, and I haven't deleted any of them either. It makes interesting reading skimming through the contacts on my phone, given some of the more unusual names ladies pick here.
Although, I'm happily single (at least for now), so there's the added benefit that I'm not sneaking off behind someones back when I get up to naughty fun, and I have two phones to satisfy some extra paranoia. One is purely used for contacting escorts, the other is a personal one, that's the way it'll stay.