It would be awesome if Marketo Smart Campaigns could be triggered by calling a webhook into Marketo.
Essentially, just going to a URL with the right paramters could trigger an entire campaign.
For example: A lead owner gets an alert that a lead has reached a certain lead score. At the bottom of the email, there is a list of functions that the lead owner might be able to do: pause marketing, start the lead on nurturing, or flag the lead for deletion. And all of these can be triggered by calling on Marketo with a simple link with the lead id as a parameter.