For general concept I've got to give it to BitPay. It's new and rough around the edges but it works. I'm also not one of those purists who demands that the wallet/blockchain MUST be on the phone itself. I've got no problems trusting a third party (BitPay is just a front-end for instawallet) but I do have a problem forcing average users to run bitcoind on a computer somewhere, forward ports to it and set up API access via their phones - that's the kind of thing that keeps bitcoin solidly in the realm of us geeks and out of the hands of normal folks.

Still, I'd like a better feature set and perhaps a choice to use MyBitcoin or some other service than instawallet.