How to disable apache logging when accessing certain directories?

How do I get apache to prevent http requests from being logged on a directory basis? I want to do something alike

<IfModule mod_userdir.c>
    UserDir public_html

    <Directory /home/*/public_html/nolog>
        Options NoAccessLog
    </Directory>
</IfModule>

You can set an environment flag whenever a specific URL is requested and filter logging based on that:

<IfModule mod_userdir.c> 
    UserDir public_html 

    SetEnvIf Request_URI "/nolog" dontlog
    CustomLog /var/log/apache2/useraccess_log combined env=!dontlog
</IfModule> 

All the related reading can be found at http://httpd.apache.org/docs/2.2/env.html Section "Using Environment Variables - Conditional Logging"

What these two lines do is, whenever a Client requests a URL that contains the string "/nolog" it sets the Environment Variable dontlog.

In the next line the option "env=!dontlog" tells the CustomLog directive to log Client access unless the variable dontlog is set. The ! negates the directive. If you would leave the ! so that it reads "env=dontlog" than it would only log access to paths that have "/nolog" in the requested URL.

EDIT: I removed the ^ in the "/nolog" regexp to work with your example and added some more explanation.