I once offered to pay a high end provider in Schrute bucks but she would only accept Stanley nickels.

Google Wallet is an option that some ladies accept.  You need to link your savings account or debit card.  Some ladies take Paypal.

Well, you can always pay by credit card to some agencies (and even some escorts) but that leaves a trace for your wife/girlfriend/LE to find.

If you're traveling, and don't know if you'll be able to find an ATM (which is really hard to do these days - ATMs are all over the place) you can wire yourself money through Western Union.

When I was traveling in the UK some years ago, I was able to get cash advances on my charge card at the American Express Office.  Depending on the type of card you have, and your credit limit, you can get a couple of thousand dollars that way.  One trip to Amex and I had enough cash for two weeks of nightly play.

I once paid an escort in casino chips in Atlantic City.  She then just went to the cage on her way out and cashed them in.  I imagine the same thing might work in Vegas or Reno.

I'm waiting to see which agency accepts Bitcoins first... or have some already started doing that?