I have done a few--not many. If I recall correctly, I was given a Fed-EX account number to ship materials to them if necessary. The problems I encountered with these is that a take out menu does not suffice. These are supposed to be covert shops (or at least were when I did them). You need (needed) ALL menus offered by the establishment for the meal period in question. At some locations this means an entree menu, a kid's menu, a dessert menu and a beverage menu. While some places print up menus on 8 1/2 x 11 that they have no problem with you taking the regular menu with you, most of the locations I have seen with Mintel are ones with oversize menus that are laminated or put in folders.
Ploys I have tried--grandson coming to visit is picky eater. Birthday dinner for gramps I want to send a copy of the menu to my daughter to make sure there is something on there the kid will eat. Outcome: I was given the throw away kiddie menu. Oops. I asked then if I could leave a deposit on a regular menu to run it over to Kinko's and make a copy so the big folks could see as well, since the birthday treat was on them. Outcome: Handed a takeout menu and told that 'everything we offer is on the takeout menu and it is the same price, dine in or carry out'. Mintel did accept that.
I went in once to ask if they could handle an office party of 18. The plan was to 'borrow a menu to show my boss'. Nobody was at the hostess station so after a couple of minutes I picked up a menu to take digital photos. The restaurant was so dark the flash insisted on going off. Rather than disturb patrons and because I still had not been greeted, I took the menu outside to photograph. It started to rain so I thought to heck with it and headed for the car, menu in hand. At home I got wonderful photos. Next day I returned the menu, and this time I was greeted. I thanked them for the loan of the menu, told them that my boss was interested, asked about the ability to handle a party of 18 and mentioned that my boss was concerned that no beverage prices, desserts or kiddie items were on the menu. The host about fell over himself getting me a kiddie menu and a take out menu that listed desserts an beverage costs.
I know some folks haul the menu to the restroom for a photo fest, but that is sort of a commitment to have an unpaid meal there.