Hi-res screenshots of web pages

Here’s one for the visitors. Do you know of any software that can produce high-resolution screenshots of web pages?

Currently the usual method is to do a print screen and paste it into the destination document. This is at (I believe, for PCs) 72dpi, and really doesn’t look too great on printouts.

My reckoning is that there ought to be a program out there that can grab images of web pages at higher resolutions, 300dpi+. The snag is that if you think in conventional ‘print screen’ terms, you’ll be getting 72dpi every time, so it really ought to be a program that re-renders the page (ie. understands HTML; CSS, etc) – maybe a Firefox/IE plugin?

I’ve seen (and written) programs in the past that take automated snapshots of websites – normally by rendering in a browser on a virtual terminal and saving the output to an image – but nothing that renders directly to a high-resolution image… any ideas?