I need the feature mentioned in the title, so I have implemented a crude token removal mechanism from the keychain (see patch attached).

However, note that storing a new token for an existing {application, service_provider} pair will not default to deleting the previous one - you need to explicitly remove it yourself if your application needs that behaviour. Also, if several items exist for the same application and service provider names, only the first one found will be removed.

Cheers!

I think this is a really important issue that needs to be resolved, imagine a Twitter app with multiple login's how can you manage this is there is no delete option to effectively log you out.