Create a little plugin that allows website users to see a visual history of where they have been on the website. It could be placed in a small bar in the bottom right hand corner of the website.

These images could be preset by the web developer (maybe icons representing each page could be setup and assigned to each page or category each page falls under in the case of blog posts). Thumbs could also pull from the largest image on the page or be created through some PHP screenshot script.

In essence, you'd have a visual back button right there in the gui!