Interesting topic as I've been wanting to do some cheap adventures on my DR650.
As to the topic of 'oops I forgot my wallet so I'll look you in the eye and and lie in the hope that you'll give me something for free', that may fly in some parts of the country, but here in the South, we pretty much call that 'stealing' and don't take kindly to it. And offering to do some sort of work after the fact, knowing full well that a business owner is not going to let a non employee around the counter, just adds to the deciet and insult.
Servers work hard for the little bit of money they make (much of it in the form of tips) and businesses today are getting by on pretty thin margins. We're a pretty generous lot here and will go out of our way to help people in need, but don't take advantage of us.
I usually run out of talent before I run out of horsepower.