Is there a way, perhaps using another web app, to know which sites I have accounts on? My Gmail account exists for almost 11 years, and over the years I've signed up on tens, or maybe even hundreds, of websites (a lot of which are already dead).
There are similar questions out there, but in all of them the answer is to log into Google and check the list of authorized apps. That's the easy case. In many cases, you just give your email address to the site as the username.
Best Answer
I think that your best chance is to search for email address verification messages from the websites that your registered.
Use keywords like
registration confirmation
verify e-mail address
...