i actually think the whole concept is dumb. just spent 45 minutes doing it to prove a point. too bad websnappr is throttling requests for the preview images.
Of course these commands can be automated in your language of choice. The only problems: firefox opens a new tab by default, so you can't close old ones; and there's no way to find out when a page is done loading.
This would be especially cool in an application like Google's image search. And @Readmore above... this definitely has a lot of potential as a mobile device app, and everyone knows the mobile internet is growing fast!