blam! has become a templating tool for writing reviews of (so far) books, CDs and DVDs.
You enter the ASIN/ISBN number of the item you're reviewing, then fill in the name and URL of your weblog, your Amazon associates ID if you have one, and your review.
blam! uses Amazon's web services to look up the metadata for that item, then produces the HTML you need to paste into your weblog, including an image of the item, referral links to Amazon, and metadata that will allow sites like allconsuming.net to pick up your review (like this one).