META LINK REL support. New feature? New Module?

Apologies if this is not exactly the right issue stream, but advice I've seen always seems to say post over here, even when we are unsure exactly which 'component' the discussion applies to.

Support <link rel='relationship'> tags in the document head

I'm aware that some people think that meta tags are totally useless, and I'm also aware that LINK REL tags have traditionally had very bad support, but they can exist, Opera & Firefox use them, I use them, accessibility browsers and hotkeys use them, and, given the amount of structural info available to our nodes, could be implimented quite easily.

It's likely that this is more appropriate in a new module altogether, or as an extension on the (non-existant?) keywords.module.

Some modules (specifically book.module and comment.module) should be encouraged to impliment this in their own way (up, next, prev etc) using set_html_head but other rel tags types like 'contents' could be global.

Has anyone given this some thought?
It will help a lot of folk who are being required to meet 'accessibility' guidelines, which I see as one thing Drupal is doing a lot to support.

Feel free to move this to an appropriate section, sorry if it's more like a forum post, but where should I post a 'feature request' for a non-existant module?

.dan.