If you have a Gmail account, did you know that you receive email to your account regardless of whether there are fullstops in your username?
john.smith@gmail.com will also receive email sent to j.o.h.n.smith@gmail.com, or even johnsmith@gmail.com – Gmail essentially ignores the full stops.
I discovered this when someone sent an email to me without the usual fullstop between my first and last name, and it’s been really useful when signing up for multiple Twitter accounts (you have to have a unique email address for each Twitter account).
Read more about it in Gmail help, note though that Google Apps does recognise fullstops in your username.