Keyword URL structure

[Forsh]

If you had a choice to structure your URL's between these two structures, which would you choose?

.com/keyword/keyword1/keyword2-keyword3-keyword4/

or

.com/keyword3-keyword4-keyword4/

Is it better to work the keywords in the URL using hierarchy, or is it better to keep URL's written short and appearing like they are higher up in the url structure hierarchy?

I am afraid I may have been rewriting everything with sample #2, not even thinking to keep them in a hierarchy, is that bad?

My site is in my sig if you wish to see my dilemma, then click on "photos" and click through and watch the URL structure not form a hierarchy, that's what I am referring to.