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Now UserLand has a means for capturing your Google keys. No, I don't think they would ever do so, but imagine if someone less scrupulous ran such a gateway. Dave previously said put a pricetag on the service asap. Trusting intermediaries and sending keys are difficult problems that IMHO must be addressed before this is a viable option. The first step is to agree on a common vocabulary for things we already have, as I describe here.
Bootstrap, bootstrap, bootstrap. Google now has a compelling service. The next step is to make it secure.