At 0.9, anafero, our referrals app, now supports arbitrary object linking to responses in addition to the action label. What this means is that you can track what specific objects are being referenced by referred sessions/users. I think this is going to be a very powerful feature addition, opening up all kinds of potential use cases.
With phileo, a need presented itself in a client project to have the same object likable (we use the term "bookmark" in this particular site) in two different places with different UI requirements within the site. I started off trying to hack the content from the widget the phileo's template tag outputs in the second case, however it quickly became a kludge. Therefore, 0.6 now has a second template tag the renders a different template, giving the site builder more control over placement and design of the like buttons.