Controlling options in admin area

Hi,

I’m setting up an install of wordpress to be used by multiple users with their own subdomains (they have their own separate database logins and I’ve modified wp-config to get the database logins from the database).

What I’d like to do is stop users being able to access certain areas of the admin area, such as the themes and plugins. This is because they’re using the single install as a shared resource, and I’d like to ensure they don’t use each other’s templates etc.

Is there any way to do this without hacking the menu.php file, and putting some logic around the themes and plugins admin files? Ideally I’d like to be able to control access to these files using a plugin to keep the site easy to update.

Thanks in advance,

D