The WordPress Signature plugin allows wordpress users to have signatures below every post.
Better bbPress Signature is signature plugin to add option for member signature for bbPress forums
This plugin allows your users to have signatures in a bbPress powered forum.
The Signature Widget for Genesis adds a signature widget on single posts only to WordPress sites running an HTML5-compatible Genesis Child Theme.
This plugin is a collection of sub-plugins for group forums. Signatures, bbCode lite, ShortCodes, Ajaxed Quote, RSS Feeds, Forum Index (and Widget), A