Or is there something a user could provide as collateral, digitally, that would not hamper the speed of the transaction? Again I am thinking of making this quick and painless for first time users of Bitcoin.
That's why Bitcoin is so revolutionary. Bitcoin is this thing you are seeking -- the thing that is like cash (final, non-reversible transaction) that can be sent electronically.
Cash is the next closest thing, but you cannot send it electronically so that is why you would need to visit a bank or other intermediary to convert that cash into electronic form for the purchase of bitcoins.
If there are lenders who will grant a credit for use with a credit card then there will be lenders who will grant bitcoins on a promise as well. There just haven't been too many of them so far, but that's probably going to be growing as a method that serves more and more.
Also, don't discount local trading. If your friend has bitcoins and is willing to let you swipe your credit card through her Square dongle on her iPhone for payment, then your problem is solved, right?