Connecting accounts

Hi there- I was wondering if there was a way to connect user accounts. So you could post as more than one person without having to sign out and back in as the other person. For example the site I wanna make is a social site for peoples characters- and people have more than one character of course- so they'd use more than one user. Is there a way to link these accounts back to one main one so you can just choose who to post as? Or who to be without logging in and out?

Also When you make a group- is there a way to post as that group like you can on facebook?

thank you- sorry if the answers are completely obvious- my boyfriend hasnt put my dolphin site up yet so I cant test these things out for myself XD

thanks in advance

Well i think it is possible by setting the cookies of the member you want someone to be logged as but it requires a big amount of work plus taking care of security. Best way will be to hire a very experienced developer. 

 Fixed, lol.