[wbillingsley]

The painful thing I've found with this is that it leaves [e-mail] as a valid email address. So there I am signing up for other services with [e-mail] and meanwhile some typo-ridden fool in the US keeps signing up [e-mail] instead of [e-mail] and I end up receiving their hotel receipts, iTunes receipts, etc.

Very few of those services have a good way of dealing with "No, that wasn't their email address they signed up with, it was an alias of mine". And while for some of these, I could presumably click the "forgot password" link and go into their account, I'm not sure that would be legitimate and wouldn't know what their correct email was to change it.