I recently mounted a Soma Mini Front Rack( http://www.somafab.com/archives/product/mini-front-rack ) and Wald basket to my Bridgestone XO-2. While it's not as sturdy as a porteur rack, Soma told me it can carry 20 pounds safely. I've used it to transport flats of strawberries home from the produce stand, carried extra gallons of water on long rides, carried my camping supplies, etc.

I should have done that a long time ago.