I'm not sure why she's not on our hair radar -- maybe she's just not famous enough yet -- but Taryn Manning is definitely an example of how an actress can go from having gorgeous hair to run-of-the-mill hair.

Wireimage.com and GettyImages.com are great places to review her hair history, but here is how she looked in what I would consider her glory days:
http://editorial/gettyimages.com/source/search/details_pop.aspx?iid=3357907&cdi=0

And here is how she looked October 20, 2004:
http://story.news.yahoo.com/news?tmpl=story2&u=/041021/482/camt10910210615&e=3&ncid=707