shawfactor

I wrote this plugin as I needed full flexibility when adding an “agree to terms” check box to your login or registration forms,
Not only does this plugin facilitate requiring users to agree, but also allows you to customise and configure the terms and conditions message, add links, and also the customise the message those who have not agreed see.
Additional features include:
<ul>
<li>User registration support</li>
<li>Buddypress support</li>
<li>Multisite support</li>
</ul>

LH Agree to Terms

Add a HTML5 "Agree to terms" check box on login or registration forms.

levi.putna

The WordPress Terms & Conditions plugin, pops up a Terms & Conditions agreement page the first time a user logs in. In addition the new users are presented with a nice fully customisable welcome message after they agree to your Terms to help them get started using your blog.
For WordPress installations setup with the multiple site option the Terms & Conditions will pop up the first time a user loges into there new site.
Features 
* Works for both New Blogs and New users. 
* Customisable Open Source Terms of Use agreement. 
* Customisable Open Source Privacy Policy. 
* Customisable Welcome Message. 
* Can be integrated into a mature blog. 
* Support for both WordPress and WordPress MU. 
* No changes need to be made to the Sign up process.

Terms & Conditions

This Plugin adds a Terms & Conditions agreement page the first time a user logs in and a welcome message for new members.

LH Agree to Terms vs Terms & Conditions