There's an extra list with books I have read but didn't find the time to write a review about. Currently, some reviews are in German only, even if I'm talking about a book written in English.
Most reviews contain some ordering links for different online bookstores at the end. Some of them - notably the Amazon bookstores - offer additional reviews for these books if readers or authors took the time to enter something.
I'd like to write more reviews but then I'd not have enough time for reading - I can only add a new book every now and then. Most of the books on this list have been around for years!
I am also extremely impressed by the new "lists" feature at amazon.com, where ordinary users can create small lists of books that share a common theme and comment on them. If you select a book, you'll often be shown a (randomly selected) list that contains that book and thus get a chance to glance at someone else's thoughts. Highly recommended, at least at the moment (early 2001).