Yeah you're kinda right.
It's the same method I used to light my avatar.
I used an HDR image, which are cool since they can store the light information without limiting it to being between 0 and 255 - like a standard image. So you can have a light source which like real life is really bright etc.
Here is an old (but still relevant) cinema 4d tutorial:
http://www.maxoncomputer.com/tutoria...tutorialID=241
I find if I'm using a single HDR image rather than a light the render time is less too - probably due to area shadows being expensive to calculate.
Of course a good light setup uses more than one light, but still. (Although an HDR contains basically all the light you need anyway.)
Edit:
Just for reference and because I can't stop procrastinating,
here is a picture showing the 3 different shadow types and example hdri lighting. The scene is a the same for each render.