Pastebud—the Javascript-based copy and paste framework that lets you move text from Safari to an email or a form on a web page—is the cleverest solution yet, but still doesn't quite hit the mark.
As you saw in the demo video, Pastebud works via two Javascript bookmarklets that you save to your Safari browser (and edit slightly). The COPY bookmark translates whatever page you're currently looking at into a text-only version, where you can highlight your desired text. This can then be moved directly to an email, or saved to your virtual clipboard (stored on Pastebud's servers, but anonymously and only for five minutes, they claim).
Pasting text back into another web form via the PASTE bookmarklet is easy—after tapping it, a green box labeled PASTE HERE is overlaid onto any open form field. Tapping that drops in your clipboard's contents, preserving any HTML that was there if the form supports it.
But, of course, there are some drawbacks. While pasting to and from different Safari windows and emails covers a lot of one's copying and pasting needs, it's not anywhere close to the convenience a system-wide solution would bring. You still can't paste the URL to the cute kitten photo you're looking at onto your Wall via the Facebook app, for instance. For things like this, being able to access Safari's URL bar would be nice, since natively, you can only export your current URL via Mail.
Also, th! e free v ersion inserts a small one-line ad for Pastebud; $5 turns this off, and also eliminates the popup that appears whenever you paste. $5 isn't too bad though, for something that's ultimately pretty convenient. If you're betting on Apple's year-plus delay on coming up with a copy and paste solution carrying on, it's not a bad investment. Check out Lifehacker as well for more impressions: [Pastebud, Lifehacker]