Signature Footer in Groups etc?

Hi All,

As I want to be targetting a profesional audience with my network once it's developed and launched, is there already a way or the ability to enable a user to create a signature in the footer of their site messages, group discussion posts and any other plugin / system feature that offers the user fellow user interaction?

I understand this may not be needed or wanted at all by hobby sorts of networks etc but for a professional subscription based network, I believe it to be imperative in my honest opinion.