Aviary has just launched Screen Capture Talon that can let you capture any webpage from any browser, by simply putting Aviary.com/ in front of the URL. You can capture a page at different resolutions or to only capture a portion of the page as well.
After capturing the page, you can edit it, add simple markup to it and save it to your desktop.

I am an avid user of Firefox’s add-on Fireshot, especially since most of my work is design related. In my search for a Skitch like counterpart for the PC, Fireshot was the answer.
Fireshot is simply an add-on, not an entire program, which makes it’s ease of use appreciated. Once added to the Firefox browser, a Fireshot symbol is placed next to your search bar. Unlike other screen capture software, Fireshot allows you a multitude of options the first two being whether to capture just the viewable portion or the entire page.
Once captured Fireshot offers a bevy of tools to make edits to the screenshot. This advantage sets it apart above and beyond the competition. The capture can be edited to include highlighting, circling, adding text to point out information, and other such annotations. Numerous file formats are available when saving the captures (PNG, GIF, JPEG, BMP)
This add-on is most useful for testers and designers, but even more useful for those writing instructional copy. Photo inserts can now be marked up and labeled to further increase the effectiveness of the material.
Fireshot can be downloaded here!
