How can I take a screenshot of a whole web page? [duplicate]

I have been testing various Firefox extension for screenshot grabbing, but none of them suited my needs.

Then I have found Shutter (0.86.3), and it is really nice. I use exporting to imageshack and FTP a lot.

The only thing I miss is grabbing the whole web page area (not just the part currently visible on the screen). Is there any Shutter extension for this or similar app with such a feature?

The GCLI no longer exists. See answer to duplicate question.

On recent versions of Firefox, there is no need for any plugins. This capability is built into the browser.

1. In Firefox, use Shift+F2 to open the in-browser CLI. This is a command-line interface at the bottom of the browser window which lets you do all kinds of awesome stuff. (I find the restart option particularly useful.)
2. Type screenshot --fullpage (this will autocomplete, so s Tab --f Tab will work; the autocomplete is shown by grey text ahead of the cursor).

That will save the screenshot as a PNG file to your downloads folder. By default, the filename includes the date and time. You can use a different filename if you wish, simply by passing it in on the CLI: screenshot --fullpage my_name.png.

Screengrab does what you want.

Edit: Since screengrab is not maintained anymore, Awesome Screenshot is a good option:

https://addons.mozilla.org/en-US/firefox/addon/awesome-screenshot-capture-/

I use nanoshot which has its own web-capturing setting.

sudo add-apt-repository ppa:nanoshot/ppa
sudo apt-get update
sudo apt-get install nanoshot

There is an amazing extension for Firefox called pdfit, which allows you to save any webpage you are currectly watching entirely (from top to buttom) in varios formats: pdf, jpg, ...