Gplus.to is a newly launched third party service to get your lengthy profile name shortened and to make it look like http://gplus.to/username . No doubt that this is one excellent app to add more value to Google Plus fans and users.
Google+ Profile Nickname
Also make sure you are just entering your Profile ID (eg: 101543526037062642773) and not the complete profile URL.
There are so many developments yet to be done by Google+ team and this new unofficial web app is just to decorate it little more with your Google+ experience. Now you can share your G+ profile easily using your shortname added with gplus.to. Hurry up and Reserve your name before someone take it.