InstaRead is Instapaper Text bookmarklet wrapped as browser add-on. Read web pages in a clutter-free, comfortable reading mode.
InstaRead is available for Mozilla Firefox and Google Chrome. You can use it from Add-on bar in Firefox (toolbar in Chrome) and context menu (right click menu).
Screenshots
Firefox:

button on Firefox Add-on bar

Open links from context menu
Chrome:

Toolbar button

Install InstaRead
Alternatives: You can try Readability or this Chrome extension for ViewText.org.
Thanks Supratim Nayak for icons.

Thank you for developing this. Very useful Addon. And thanks for supporting chromium.
Could you check, if your chrome add-on is working fine? I have Chromium 15.0.861.0 and when I go to https://chrome.google.com/webstore/detail/njmpbcjaomahmmcbeacllaknjkadpilc?hl=de&hc=search&hcp=main#
to install and click the install-button, all I get is the spinning circle but this process is never finished.
I really like your add on! However it would be nice with some settings like being able to open the Instapaper version of a page in a new tab.
Love the chrome extension. Is there a way to email the text article once displayed – the whole text article, not the link – other than copy/paste manually?