In here is an archive of a ux experiment that I tried in 2010 to allow for touch-accessible href's/title attributes. The context was a 2nd generation iPhone on iOS 3 I believe. My primary problem was when I went to a webpage that I couldn't find an easy way to see where a link would take me without actually going there. I decided to think about this information as hidden, and the best gestural metaphor would be to uncover it. To do this, I created a bookmarklet that would move the link out of the way when you moved it left/right and left behind would be the uncovered information that you could not get before. The concept could just as easily be extended to let you see the hidden joke on xkcd in the title attribute, but I don't believe I took it that far.
I call it an experiment because I never took it very far. It solves a relatively esoteric problem pretty well, but when validating the idea, I mostly got feedback that this wasn't a big problem for everyone else. Another unsolved problem is how to make the experience better for designers to control how the interaction would impact their site. My plan was to simply document the important selectors, but it wasn't ever done.
Anyway, here it is if I ever get back to it, or if you happen to stumble across it. It only supports touch events, so emulate touch events in chrome to see it in action or view it from ios.