Get Post Image is a plugin for WordPress 2.0 and higher that allows you to retrieve images contained in posts and display them in a custom manner.
Though the plugin helps you do all that what is said, it had a small bug (or was it intentional), will need to ask Andrew. The problem was identified only after we implemented it in the Asianet Portal – Kerala Online. With about 10K hits a day, the whole process was loading our web server which was a Dual Xeon with 4G RAM. I found it really baffling, and went on a wild hunt, and identified a lot of about 15 to 20 internal requests per external request of a page.
The hunt finally came to the place where the problem was on line no 252,
$imagesize = @getimagesize($img_url);,
which was changed to
$imagesize = @getimagesize($img_path);.
And the server started to breathe again.