I read with some interest two posts on the Amazon Affiliate Blog today, and learned some useful information!

The first one is for refining search results when linking to Amazon, here are the bits you need to know:

These can even be combined (something I may play with later and hence the reason for blogging it here!)

Example 1: Canon or Sony digital cameras:|Sony

Example 2: Children’s books about pirates by John Matthews,John&select-author=field-author-like