[mrweasel]

Not exactly what you're looking for, but I talked to a developer of a solution that integrates with online banking and recognizes subscriptions and allow you to cancel them directly from your online banking thingy.

Only downside is that it's the banks that has to do the integration. I can't really figure out how they deal with the actual unsubscribing bit. The subscriptions people are most likely to want to cancel has to be those who with the worst unsubscribe process.