Hurry! Only until the 10th of January, you can change your handle! Note that it will be possible to roll back the changes or change the handle again only after a year.
You can change your handle to the new one which wasn't used before by anybody or which was used by you before. Soon, the links like http://codeforces.com/profile/Alex_KPR would automatically redirect to the actual profile.
Talking about handles I always reminisce the following story. Once a user wrote me the message: "Please change my handle from I_love_Valya to I_love_Sveta, as I no longer love Valya ..."
Happy New Year!