Tag Users and Taxonomy terms in body field of a post I am building a Social Networking site in drupal. My client requirement is to tag users and taxonomies using a '$'. For example "$john" will tag a user john with that post. and "$Arts and Entertainment" should tag the Taxonomy term to the post. 

I tried hashtags module. But it is for tagging the words in body with a "#". The words are tagged under a separate vocabulary called "Hashtags". 

My functionality needs twitter OR facebook like tagging of both users and Taxonomies(with a autocomplete Dropdown).

For tagging the taxonomies, I have created a separate field called Industry Tags of type Term Reference in that content type. This field will store the mapping of that particular node to the Industry Terms(Taxonomy Terms). Iam not going to display this Industry Tags field in the frontend. Instead of that i have to save the terms that user enters in the Body field prefixed with "$" to in this field. Example: "$Education". 

Also for tagging users i can use "User Reference" in the same manner i mentioned above for industry tags. But i need the functionality to be something similar to twitter / facebook.

Please suggest me some ideas for implementing this.
It will be interesting logic to figure out whether $art is a user or the start of the $art and entertainment taxonomy term, but, regardless, what you are most probably looking for is an input filter that can recognize a pattern in the text and then both create a link to either the user or taxonomy term as well as actually tagging the node with that taxonomy term if it is one.

A start might be to take a peek at the Hashtags Module and change its use of # to $ for the taxonomy portion and then extend it to include users.