Idea for an alt-client mode...

[MoonShadow]

Say that you have a client on your home computer, be it a full client or a Electrum style light client.

And you have an app on your cell phone that both lets you transact over the Internet, as BitcoinSpinner does, but it would also be ideal if it could also transact over an ad-hoc wifi connection, whenever Internet is not reliable or available.

Take this as an example...

The cell phone client is neither a light client of any kind, nor is it independent.  It's dependent upon regular help from the home computer client.   The home computer client creates a special many-output transaction that sends a set of btc values to a set of newly created addresses.  The home computer client then sends a copy of this large transaction & all of the keypairs to those addresses to the phone client.  The phone client can then create transactions of any amount within a range of values several times before it needs to reconnect to the home computer.  While it can't utilize the change outputs in it's own transactions, it can continue to reference to that single many-outputs transaction until the outputs are consumed.  While this would not really change the risk model for the receiving merchant, it would remove the need for full time Internet access for the spending client.  The cell phone client would only be able to spend, and could not really verify any funds received, but the vast majority of the time we spend cash from our physical wallets, and reload them from our bank account when we see the teller or ATM.  In practice, however, the phone client would still be able to know the next receiving address that the home computer client is going to use, and potentially receive funds (that can't yet be respent) by accepting a transaction over an ad-hoc wifi connection itself.  While this would have a terrible risk model as compared to a full client with live Internet access, if you know the person in meatspace your risk model is already different than online.

Thoughts?  What are the downsides?  Any improvements that can be thought of?