Virtual Multiblog for WordPress allows you to run more than one blog off a single install of WordPress. Each blog is managed as a complete separate install — separate admin sections, separate users, etc. They will happily co-exist with different themes and plugins activated. The biggest advantage is that you will only have to keep one set of program files up-to-date, and this method should be expandable to as many different blogs as you like.
FeedEntryHeader Allows you to add a copyright statement and a link to the original article, to the TOP of your feed entries, in an effort to hamper content scrapers.
Custom Permalinks gives you ultimate control over your site structure. Lay out your site the way you want it. Set the URL of any post, tag or category to anything you want. Old permalinks will redirect properly to the new address.