Here are two very simple bookmarklets that let you jump between corresponding titles on Netflix and IMDB. I wrote these because the Netflix reviews and rating suck.
To use: Simple drag these two links onto the Links bar in your browser, or alternatively right-click on them and 'Add to Favorites'. Don't click on them from this page, because they're useless.
You'll them be able to jump between the same title on Netflix and IMDB using the links. Because they just use the <title> of the page, they'll allow you to jump from many other sites too.