Something I’ve found via FStoppers.com.
You can download onOne plugin Perfect Effects 8 for free until the 28th of Jan.
Not used a lot of plugins although I’ve bought Color Effects Pro from Nik/Google – has some good functionality but don’t use it often. But this one is free so might as well give it a go.
Edit: Just noticed they also have some free presets for Camerra Raw, Lightroom and Apple Aperture : http://www.ononesoftware.com/free/