There have been lots of links to automatic website thumbnail generators on sites like reddit and hacker news today, including webkit2png and CutyCapt. Well it just so happens that a few weeks ago I wrote my own website thumbnail generator, and today I got around to putting it on GitHub.
The code is based on Matt Biddulph's screenshot-tng script, but heavily modified to be more user friendly and provide more options. It uses embedded mozilla for rendering, and therefore requires the python-gtkmozembed package.
You can specify a resolution to take the screenshot at, and also a resolution for the thumbnail. When generating the thumbnail the aspect ratio will be preserved. You can also specify a delay, so that the screenshot is only taken so many seconds after loading the page. Here's an example of running PyWebShot with 3 URLs, and the resulting images:
$ ./pywebshot.py -t 500x250 http://www.coderholic.com http://geomium.com/update/598/ http://jobs.plasis.co.uk
Loading http://www.coderholic.com... saved as www.coderholic.com.png
Loading http://geomium.com/update/598/... saved as geomium.com.update.598..png
Loading http://jobs.plasis.co.uk... saved as jobs.plasis.co.uk.png
It you have a huge list of URLs you'd like to generate screenshots for you can put them all into a file and generate images for them all with the following command:
$ cat urls.txt | xargs ./pywebshot.py
For more details and the source code see the PyWebShot project page on GitHub.