How do I hide/ prevent new blogs from accessing certain parts of the admin panel?

Membership & Marketpress plugins, Wordpress Multisite 3.1.1

Hi, I saw the Buddypress hide widgets plugin, but I'm not using buddypress. Is there a way that I can hide certain parts of the admin panel from new blogs? I want customers to be able to upload products to their store and create posts but not fiddle with widgets, plugins etc

I saw this option, https://premium.wpmudev.org/forums/topic/wpmu-new-blogs-default-useradmin-roles
to set the user role, say as an author, but it doesn't seem to be compatible with the most recent version of WP 3.1.1.

Suggestions?