Find a small rechargeable one that will fit in your shirt pocket. The more gigs the better and get a 'one button record' model and familiarize yourself with where that button is. I put a couple of drops (carefully) of epoxy on the record button so i can feel it through my pocket. It's your best insurance policy when out and about carrying. If you're ever approached by a nonbeliever or an unruely manager, officer et al, just tap the button. It's all recorded if there is ever any question.