The power of bookmarklets is still to be seen in many situations. Consider the "Where Are You From?" (WAYF) problem, a common issue with federation technologies. The simple question of where to send the user to complete a federated authentication is one of the more complicated and error prone issues in identity federation. The key metrics for any WAYF solution are that the user should have the opportunity to choose any relevant identity context and the process should be hard for a RP to subvert.