Django Book: Comment on text blocks
The Django Book offers an inline commenting system where you can offer comments on a specific block of text. Top screenshot shows normal view, bottom one shows what happens when you click on the “1” comment icon. More details at [tx Collin]

Cre8d: Equal billing for comments
Comments are at the top of the page at cre8d — post top left, comments top right — so visitors can catch up on thread action without scrolling.

Bats Blog: Reply on the spot
bats blog
At The NY Times Baseball blog, the editor responds to commenters at the spot of the original comment instead of later in the thread.