Show different home page, depending on role?

Is there a way to show a different home page depending on the role of users on my WP site?

I ahve a site that is for writers, publishers, reviewers & readers, and each would be interested in different things on the site, so it would be good to be able to let them see what they would be interested in when they come along.

Also, it would be good if anybody knows a way to show specific sidebars to different roles.

Thanks.