How it works:
pastebud enables round-trip copy and paste on your iPhone or iPod Touch, between the two applications that matter the most: Mail and Safari. And through a clever combination of web services and bookmarklets, it does it without requiring a jailbreak or App Store download.
Guess what? I just copy and pasted that. From a webpage. ON MY iPHONE.
I need not say any more. Pastebud.com is the best copy and paste you're going to get for now.