I personally would never give out my credit card.  Cash is always king.  Cash advance rules on credit cards will change when the new banking reforms go into effect this year.  Instead of the debt sitting at the bottom of your balance and not being able to pay it off before regular purchases, it will sit at the top.  You won't incur much interest charges if you pay it off (or at least the cash advance amount) by the end of the month.

"ONLY HOBBY WITH CASH"
"ONLY HOBBY WITH CASH"
"ONLY HOBBY WITH CASH"

Two reasons for this.  The first is the paper trail and possible fraud issue. The second and, to me, the far more important reason for not using a credit card is to avoid spending money that you can not afford.  Hobbying is a non-essential activity but good pussy is addictive. Don't use a credit card or a cash advance and only hobby when you have the discretionary funds to do it.

BG is very wise.
Always play with CASH.  
Never play with CREDIT.  
NEVER play with the rent money, grocery money, etc.
If you have to put off a date for lack of funds it will be good for your disipline.

NEVER leave Tracks.  It is SLOPPY.  People who are sloppy get caught.
skb

A paper trail, definitely.  But that's more of a concern that your SO finds out than LE.  The only time that comes into play is if you use an agency that gets nailed for taxes or money laundering.  LE can't do anything about your records with an indy.

Fraud can happen and may happen.  If you screen your provider and she's good and reputable and has some history under her belt - then it's more likely the guy at the corner gas station is going to commit fraud than she is.  

Oh, and the comment about trusting a "girl in the field" with that information is basically an ignorant point of view.  We are providers...  minor misdemeanors, not felonious and abusive criminals.  Are there some bad folks, sure, but the  that we can't be trusted as a whole just because we do this for a living is ludicrous and insulting to a degree.