QuickMyAnimeList is the dream Chrome Extension for you with a MAL account!
Move your cursor to the top right corner of your window, and click on the QMAL icon. That's it. It opens a popup window right in front of you so you don't have to open a new tab, or break away from the awesome IMDB page, etc.
Using this one single popup window, you can search for anime, view detailed information about a specific anime, view your list, and much more.
If you stream anime regularly, QMAL will be extremely helpful! It detects a streaming site automatically and asks you if you want to update your list or not.
It saves a lot of time from going to the MyAnimeList page, searching for the anime, change the episode count, and go back to watching the next episode.
This extension is open source on GitHub, at http://viid.me/qlsNu9.
Original forum thread is at http://viid.me/qlsB6J.