This plugin allows you to easily add and manage text, php code or javascript in in the comment form area of every blog on a Multisite network.

It also integrates perfectly with Farms '100 big ones' theme pack (and any subsequent theme packs)... the code is already in each and every theme.

You can see it in action on Edublogs - where the top of every comment area has either an invitation to sign up at Edublogs or a link to where users can change their avatar (if they are logged in) and a 'Share this' button... it works a treat :)

For example:

 

Of course you can use this for whatever purpose you like though, from placing advertisements into comment forms - or even calls to action and simple links.

If you're interested in this plugin, you might also be interested in:

1. Ad Widget -allows you to place advertisements (or other messages) in any sidebar based on simple rules (like if the visitor came from a search engine)

2.  Avatars - sitewide comment anduser / blog listing avatar plugin... that just works!

3.  Supporter Advertising & Upgrades Advertising - simple automatic advertising plugins for our two key premium blogging applications

Enjoy!