Customised Short Url
Having tried trial versions of various offerings, this was the closest to meeting our requirements. SharePoint Sense were willing to customise it, in particular our requirement was that it be made to prevent the creation of links to external resources, as we did not want an implicit approval of any links outside our SharePoint environment. After several iterations the product went live about a year ago and has proved to be very popular with our user-base.
SharePoint Sense were willing to customise, now meets our very specific needs.