User level modification

Hello,

I just started a website for a student association. Some parts of the site are private, so I enabled the students to register and login to see these. I give them all level 1, beause I don’t trust them with full posting rights (they might get drunk), but I’m willing to let them post links to my links-page. Only, that requires Level 5.

Is there any way to alter WP to let Level 1 users post links as well, but nothing else?

Thanks!