Gmail doesn't recognize dots (.)

Do you know that in GMail, the First.Last@gmail.com and FirstLast@gmail.com both are same?

Yes, thats true. Gmail doesn't recognize dots (.) as characters within a username. This way, you can add and remove dots to your username for desired address variations. messages sent to your.username@gmail.com and y.o.u.r.u.s.e.r.n.a.m.e@gmail.com are delivered to the same inbox, since the characters in the username are the same.

Keep in mind that hyphens (-) and underscores (_) can't be used in a Gmail address. Also, usernames are case insensitive, so it doesn't matter if you enter upper case or lower case letters.

I came to know about the above recently when I saw some mails in my Spam Folder, which didn't had the dot (.) in my eMail address.

This is what Google has to say about it.