Screen capture utility for google chrome

It's easy to use this extension
to capture visible content of a
tab, a region of a web page,
or the whole page as a PNG
image. You can also edit your
captured image before saving
it as a PNG image.
Highlighting, redacting and
adding text are supported. What set this extension apart
are:
- Super fast when capturing
page image, esp. for large
pages
- Support horizontal scroll for large pages that do not fit in
one tab screen horizontally
- Intelligently detect floating
objects on a page and avoid
repeating capture of the same
floating objects if whole page capture requires scrolling
- Works on Windows, Linux
and Mac New in Version 3:
- Capture Region can now
capture a region bigger than
the visible part of the page
- New editing tools: rounded
rectangle and oval highlighting
- Supports copying the
captured image to clipboard
on Windows and Linux.

Link: https://chrome.google.com/webstore/detail/cpngackimfmofbokmjmljamhdncknpmg