What would be better than sorting by "Average Star Rating" ?

Hi

My client is looking for a ranking system for his products (which have been reviewed) that is more useful than "Average Star Rating".

As he correctly points out, the problem with "Average Star Rating" is that a very low numbers of ratings it becomes totally unreliable. For example suppose we had 100 reviews averaging 4.8 stars, surely that is FAR better then 1 review of 5 stars, but it's Average star rating of "4.8" is obviously lower than the one review whose average is "5" !

Given that the user does not know nothing about any of the reviewers, and thus can not really trust any of them individually, what is the logical solution of number of reviews vs Star Ratings?

i.e. What is the best sort order to display reviewed products in ?

Because sorting by "Average Star Rating" clearly doesnt make any sense (at low numbers of reviews).

With thanks

John

P.S. I am not a mathematician (I am a humble web designer), but I am hoping that there is simple solution to this problem.