Found this plugin called WP-Amazon (check out the site here: http://manalang.com/wp-amazon/). Once configured it adds this button which allows you to search and insert content from Amazon into your post.
So just to try it out, in this post there should be an Amazon link to Leonard Cohen’s I’m Your Man CD.
Unfortunatelly it doesn’t work in Firefox — well it does, up to the point when you want to add the HTML code for the item in your post 🙁 Don’t worry though, I’ve already notified the guy! Also it only generates simple links — rather than the whole IFRAME, which is really what I was looking for. One thing that would be good for this plugin is the possibility to wrap the HTML coming back from Amazon into a div class=… — which is what I do at the moment, just to make sure that the pictures don’t break the alignment in my post (I typically float the div either left or right). Again, I’ve notified the fellow so maybe there will be an updated version soon.
Still, it’s better than having to log into Amazon each time and generate the HTML by hand, huh?