Here is a list of facebook aps that you may be interested in for your blog.

Social RSS Social RSS allows you to add your blog/favourite RSS feeds to your wall, boxes tab or a dedicated tab on your profile or Facebook Page. It updates automatically and lets your readers subscribe to the feeds if they wish!
Poll  is a simple facebook application which lets you to create polls for your fanpages and profiles.

Blogvote is a simple facebook applications for bloggers which lets you to vote for other blogs and promote your blogs.

NutshellMail  helps to maintain your online activities which will deliver your facebook activities in a single e-mail digest.

Yakket allows you to synchronize your twitter updates with your facebook status.

RSSGraffiti  Unlike other applications this app lets you to publish mutliple rss feeds to the walls of your facebook profiles,fan pages and groups.

Webaddress is a simple facebook application which lets you to maintain your mutliple online profiles in a single link.

Tag Biz Network ApplicationTag Biz is a business network application developer. Our focus is to create business network applications that operate within social networks. Tag Biz is a free application that provides you with a customizable business card, a Tag Biz directory listing, and the ability to create a business network with all your Facebook friends.
Simplaris Blogcast lets you to blogcast your latest posts in your blog.

Webprofiles  lets you to connect your social media accounts like twitter ,bebo,my space etc.., to your facebook profile.

Friendmeup is a simple facebook application lets you to connect your youtube,linkedin and twitter to your facebook profile.

Twitter is a simple facebook application which lets you to synchronize twitter updates with facebook.