I’ve had an idea for a Firefox extension. It’s probably a bit niche but I’m sure some people would use it; myself included.
Basically, it would allow easy importing of PGP public keys on web sites to your keychain. It would analyse the page you are currently viewing to see if it can do anything, and if any keys are found, pop up an icon in the status bar, like with web feeds. Then, to import them, just click on the icon and it’ll run the PGP or GnuPG (or whatever) executable and import the key to your keychain.
All it would need to look for is something like this:
<link rel="pgpkey" type="application/pgp-keys" title="PGP public key" href="key.asc" />
-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: PGP 8.1 - not licensed for commercial use: www.pgp.com
[Load of garbage]
-----END PGP PUBLIC KEY BLOCK-----
Not too difficult, non?
I’d do it myself but I wouldn’t really know where to start, and don’t have the time to learn XUL and whatnot.