As a web developer, just like a can specify a print-specific style sheet using <link media=print rel=stylesheet href="/print.css"> which is automatically used when printing, I would like to be able to specify a print-friendly PDF version of the HTML page which is automatically used when printing, e.g. using <link rel=alternate media=print type="application/pdf" href="/article.pdf">.
There is only so much you can do with CSS, especially with paged media, so sometimes you need the full capabilities of PDF.
This feature would not only be useful for regular content pages but also for online word processors such as Google Docs.
I believe this feature can be implemented based on existing web standards.