You forgot sponsored posts... It's a little different from a product review, but it's along the same lines. If you can write up a quality post that's not overly spammy or promotional, then it's a win-win. Just make sure you know how and when to mention to your readers that posts/links were paid for.

Demand for these kinds of posts have increased lately (I'm guessing as advertisers struggle to keep up with Google's updates). If you have a strong (ie visible) blog, with at least a PR of 3, you'll get submissions. If your PR is 4 or 5, and you can write well, you can get $150-$300 a post. (It's better to write your own post, because submissions from advertisers tend to be too promotional or poorly written.