That sounds almost exactly like what I do.
Except, of course, it's not always a shoe thing. I've done really stupid ones as well, any competition with a kiss as the bet works.
Some other places it has worked:
- Post clubbing we were deciding between two spots to grab some food, and I bet a kiss that location x was closer. Proved it on my phone and got the kiss, then f-closed after food.
- Bet that I had more facebook friends than her, again proved on the phone. We
- This girl was from albania, and she swore to me that it was the mediterranean sea next to her (we were talking about beaches). She was wrong, its the adriatic sea. (She wasnt the brightest, but I did it

)
This would work well with a wingman. Just have a pre-determined question, and have him verify that you are correct, if no internet is available.