As an alternative, you could register a domain with a catch-all email address and simply register for new services on the fly using a unique string for each site. Have the catch-all forward to your main email account. For example, I would sign-up for HN using hackernews@marak.com and for Reddit using reddit@marak.com Simple and effective.
With a service aggregating these, we see many users from NBox. Perhaps this is not a concern for your use case, but it seems a tradeoff worth considering.