I wonder what would happen if I gave my =@[mydomain.tld] (mydomain is not my domain :)). I have such an address, but haven't tried to actively give it to anyone outside of people who hit my website. Probably a major confusion.

There are a lot of funny looking e-mail addresses one can create by crafting a local part with acceptable symbols, or by using quotes. Say:

   {+}@abc.tld
   !@abc.tld
   ?@abc.tld
   {|@abc.tld

I have kept a throwaway at gmail@surname.com to have fun watching people type it the other way around.