Dennis

This plugin adds to the signup page of WordPress MU a checkbox for TOS and/or privacy policy.
This plugin is an older version and a newer version will be published in the near future.
See the installation tab for instructions to setup this plugin.

AGB-Checkbox

This plugin adds to the signup page of WordPress MU a checkbox for TOS and/or a privacy policy.

Mustafa Uysal

LettoBlog

This plugin adds a TOS (Terms of Service) field on the multisite signup form. (Such as wordpress.com TOS field)
<h4>Translations</h4>
<ul>
<li>English (en_US), built-in</li>
<li>Turkish (tr_TR), native support</li>
<li>Persian (fa_IR) by <a href="http://wp.namoblog.ir" title="Morteza Nazari" rel="nofollow ugc">Morteza Nazari</a>, thanks!</li>
</ul>

Multisite Tos

This plugin adds a TOS (Terms of Service) field on the multisite signup form. (Such as wordpress.com TOS field)

AGB-Checkbox vs Multisite Tos