Well say there's a new review for a product, and there's a link to thsi new review on the index page.
When you click on it the link could be like: http://www
That way when you click on it your browser auto scrolls down to the latest review on that product page. All it needs is html anchors <a href="#[review/product number]"/> in showproduct and showcat (to do the same for cats), and a quick update to the templates.
That make sense?
Sorry, hard to describe some things techncally as I never tend to chat "code" to others, hence don't know some of the common terminology.