Till the time Google+ comes up with its own Vanity URL structuring and support, a third party service has already introduced vanity URLs for Google+ profile and the short url does not look odd at all. It looks as if the service is from Google.
This service is called GPlus.to
Just give your profile id and preferred username and get a short vanity URL as gplus.to/likanpatra
As simple as that. It is good to be used unless Google launches its own which I am sure will be very soon.