adambrenecki

#1 already exists in the form of S/MIME, which uses the same kind of certificates as SSL and TLS do. Problem is, the certificates cost money (with the exception of StartSSL's) and basically all webmail clients don't support them.

(Aside: It does make sense why webmail clients don't support sending S/MIME email, but I'll never understand why they refuse to do something useful when they receive a S/MIME signed email. If they did, that could pave the way for something akin to what EV does for the Web, so that I could look for a green bar that says "this email is signed eBay International AG" and know I'm not being phished, for instance.)

There is the HTML5 Offline APIs for that. If you have an offline-capable web app, I think it should be possible for a tool like ManifoldJS to find out all of the assets it requires and package them into the app. Whether it actually does this, I don't know.

I don't think that's what it's saying at all. To me, it reads as though it's basically saying "one person can't remember really secure passwords for every site, so use good passwords for important sites, and bad passwords for unimportant sites".

It actually talks about choosing how secure to make a password based on importance and "the probability a given account password will be compromised", but I don't really see how users are going to evaluate the latter.