Just like you do on social networks!
Hashtag WP brings hashtags to WordPress and BuddyPress.
Use hashtags in posts, pages, comments and BuddyPress now.Now supports BuddyPress!
BuddyPress support has been added in version 1.0.5! You can now use hashtags in activities and comments.Hashtag widget
An hashtag widget has been added in version 1.0.3! The widget is using the same style as original tag cloud widget, so it will work on any themes already.