WPBook, the WordPress plugin which lets you bring your blog posts into facebook, has been updated to version 0.8.1. (You can view this very blog in Facebook as an example, assuming you’re not doing so already).
The main updates were in the 0.8 release yesterday (0.8.1 is just a bug fix to that release). In 0.8, you have the option to enable an “Invite Friends” link. See this section of the admin panel:
If that’s enabled, you’ll see something like this inside your facebook app:
People can use this to invite their friends to your facebook app. (Of course you can also use it to invite your friends to your own app – 15 per day).
If you’re interested in getting involved in development / support of this plugin and others (especially related to educational use of WordPress), check out Scholarpress.