Works exactly as promised -- right-click still works perfectly, but if you hold down the right button for just a split second you can scroll with ease. Very, very, handy.

(I had an Apple iBook, on which you could scroll effortlessly by simply using two fingers instead of one on the track pad. Now using a Sony Vaio -- which is nice but doesn't have a scroll pad at all, so this app is extremely useful. If there's something similar that makes the 'two finger trick' work, I might go with that instead; but for now I'm pleased.)