Some good resources within that, but I 'gave up' on the idea as it would require too many resources. I used the favicon of the site instead to 'tie-in' the link.
I made an assumption that the screenshot is not of a site on the same server - like Googles search results now provide a screenshot. You know what they say about assumptions :-)
Or so I thought. See http://stackoverflow.com/questions/757675/website-screenshots-using-php/
Some good resources within that, but I 'gave up' on the idea as it would require too many resources. I used the favicon of the site instead to 'tie-in' the link.
Here is a good script: html2canvas
I found this place after A LOT of googling. You can use a really simple API to auto-generate screenshots and save them down.
MPZImg.com
As an example, i just lifted this from the API page... <img src="http://serv.mpzimg.com/?uid=APIKEY&mw=200&mh=350&theURL=http://news.bbc.co.uk">
Hope that helps.