Hi Jared,
People building interplanetary spacecraft are definitely interested in solar sails. They would allow us to put spacecraft in some interesting orbits that would be very useful for studying the sun and solar wind.

So people are working on solar sails. There is still a ways to go, yet, though. I don't think there have been any successful solar sail flights yet. (I could be wrong on this - I am not a solar sail expert and an not up on the latest things).

Terry