I just finished the brown paper-bag test. I put 4 different products on the bag and let them sit for 24 hours. Then I took at look at the ring around the product and you can see how much of the product is an oil (or oil-like substance). It can give you an idea on how it will affect break-out prone skin. I'm sure it doesn't matter much for dry skin.

Here are my findings:
1.) DCL chem-free SPF 30 was the oiliest (and its an oil-free product)
2.) tied with Skinceuticals Physical SS and Neutrogena all-physical
3.) DHC sunscreen (all physical also)
4.) Vanicream (not a sunscreen) but had almost zero ring around it

Thought it was interesting, not sure the results mean all that much, but the one with the most oily ring gave me some breakouts.

-Kevin