@amitu

Gmail uses keyboard shortcuts "j" and "k" for jumping from one mail to next, while Google Reader uses them for opening consecutive blog posts. They are incredibly handy once you get used to them. In-fact once you get used to them you miss them everywhere.

Here is my girlfriend-not-free-for-movie-so-I-will-code project, jackass! It is a jQuery plugin, as well as a bookmarklet you can use, so that you can add j-k-keyboard-assignments on any page you come across.

Instructions for bookmarklet: jackassify current page.

Firefox: Drag and drop the above link to bookmark menu or bookmark toolbar.

IE: Right click on the above link, and select add to favorites.

Then go to any page, locate the above link in your bookmarks/favorites, and click on it.

If you like it, you may want to install it as Greasemonkey script.

PS: You can just click on the above link to see it get applied on my blog, and press "j" and "k" keys to experiment.