folder names ?

[s2kinteg916]

With google

is there less weight using

widgets.com/contents/red_widgets

vs

widgets.com/red_widgets

[lo0ol]

The latter. "widgets", for example, shows up 2 out of the 4 terms there. In your first example it's 2 out of 5. The higher keyword density of your URL the better- ie, ideally you should have your keyword in there and less of anything else.

[bugsy]

"red_widgets" will be interpreted by google as a single word. Use a hypen instead of an underscore (i.e. use "red-widgets"). Only then google will use that as "red widgets"!!!!!!!

[Chris]

The first result does have less keyword density but with URLs the difference will be so minor it is not something you should overly worry about.