Thanks for responding. I like the idea, and Square-like services will make card transactions easier in the future. But I really think you need to focus on this cash/large transaction problem. I've never thought about taking a check for "cash" to a bank, but I highly doubt it will work for a large sum of money, especially if it isn't your bank. My experience with cashing check at banks other than my own is they either refuse, or if the check is drawn on their bank they will do it for a fee.
Here is a list of reasons I have needed large amounts of cash:
* Last week a friend needed cash right away, I loaned it to them. That friend actually had the money in the bank, except that there are no local branches for my friend's bank. After this experience I think my friend will be getting a bank with nation-wide branches.
* I've never taken out a car loan, I've always paid with cash or a bank secured check (money order). Try buying a car with a personal check or debit card.
* Buying a MacBook on craigslist. Random people don't use Square.
* I use to modify/build cars. Buying used engines and parts costs a lot, cash or money order required.
* Neiman Marcus only takes AMAX. Visa debit cards are useless there. There isn't much you can buy at Neiman Marcus that is less than an ATM max.