That sounds like a fun idea for an app/service. You provide it with your base email address or custom domain and it generates a couple random words and keeps track of what service you used it to sign up for.
I spent a little time thinking about this concept and how it relates to just having dummy account you control, for giving to services you don't fully trust.
As long as you use a secure password, and you don't use the same one. I don't see alot of difference, but the ability to sandbox each service to a list of email accounts, so that the attacker never knows the master account, would be an extra layer of security.
Utility exists here. I just don't think there's enough utility to justify the work.
I use something similar already. I've a domain that is used purely for my email. Normal addresses like webmaster@ are rejected. A script on the server takes the domain I am registering for a service on (eg "google.com"), generates an random-looking but deterministic address, and creates an alias for that address to my real inbox.
End result is that everyone gets a unique email that can't be guessed, I can nuke an address as soon as it starts sending me spam (often) and my true inbox is typically completely clean.
I initially made the mistake of trusting my bank and utility billing systems with my real address. Turns out my power company had their database compromised, and when I called to inform them they refused to believe me (like Dropbox).
A good five years ago I got two phishing emails to two unique addresses that I had used to contact a local bank. They also refused to believe me, and it was basically my fault for not securing my computer. Somehow.
