This post is the fourth in a 5-part series that will identify the top 50 Facebook apps (10 each in 5 categories). Be sure to check out Part 1: Work, Part 2: Play, and Part 3: Media, as well.

Scrawl Pad adds an editable text box to your profile that any of your friends can edit. While that makes it marginally less useful (since your friends can change anything it says, it's probably not suitable for important notes), it is still useful for sharing quick information with friends or coworkers about meetings or memos, etc. It blends very well into your profile and almost feels as if it should have been there all along.

Mobile

The official Mobile app from Facebook adds Facebook functionality to your mobile phone. View and upload photos directly from your camera phone, or send and receive messages, notes, pokes, and Wall posts using text messages. The mobile application also includes a phone book that lets you look up your friend's contact info.

HTML Box

HTML Box is an app that lets you add pretty much anything to your Facebook profile. You still can't get around the no autoplay rule that Facebook has imposed on developers, but with HTML Box you could add almost any photo, video, text, or flash animation/application you can think of. In a way, HTML Box lets anyone have their own custom Facebook app running on their profile (i.e., this is perfect for advertising your website or business via your profile!).

ChipIn

ChipIn is how you raise money on Facebook. Using the ChipIn application you can solicit funds from your friends for an event or collection and keep track of everyone's donation. No one actually gets charged until you reach your goal. [Austin from ChipIn tells me that this is no longer the case, and funds are now added immediately after "chipping in." -- Ed.] Trying to raise $100 for Bob's birthday party at the office? Install ChipIn, set $100 as your fundraising goal, and ask 20 co-workers to each chip in five bucks. The widget does the rest for you, collecting funds using PayPal and even keeping track of how far you are from your goal with a visual status indicator.

NewsCloud

NewsCloud is a social news application for Facebook. The NewsCloud app lets you submit, read, comment, and vote on stories from within your Facebook account. It also supports videos from the Daily Show and the Colbert Report. NewsCloud users can form and join "clouds" (groups) that focus on a specific topic of news, and can access Facebook's built in share utility to easily share stories with their friends.

my RSS

my RSS is a simple RSS reader for Facebook. However, it's not really the greatest way to consume RSS feeds, because if you subscribe to multiple full text feeds it just displays them all one after the other on a single page. I also couldn't quite get the feeds I subscribed to to display properly on my profile. Hopefully the developers of my RSS will continue to work on it and improve on the UI because a full fledged RSS reader inside Facebook is a very useful application. Even not quite fully cooked, this was the best RSS reader I could find on Facebook.

Files

Files, an application by online file storage company Box.net, allows Facebook users to share files from their profile. Each user gets 1GB of free space and their files are displayed in a box on their profile for anyone to download. The application is a snap to use, but I really wish there was a way to restrict files to certain friends or at least certain groups of people.

Carpool

There's really no denying that Carpool is a useful app, and one that will only get more useful as people join. Carpool does just what it sounds like it does: it helps people arrange rides together. If you need a ride home from school or what to arrange a carpool to and from work, this app can help you find like minded people in your area. The developers are also working on making carpooling safer by helping you find rides with friends, or friends of friends who at least aren't total strangers.

Price Tracker

Price Tracker is a useful little app for Amazon addicts like myself. The application keeps track of the price history for items on Amazon.com, Amazon.ca, and Amazon.co.uk and notifies you when the price changes on an item you are tracking. The idea is that because the price of many items on Amazon changes rather frequently, by monitoring them with Price Tracker you can assure yourself you won't pay top dollar if you don't have to.

Cookbook

What's for dinner? Cookbook, a social recipe sharing app for Facebook, makes that a much easier question to answer. Browse, create, and share recipes, and see what your friends are cooking. Cookbook has 1588 recipes across eight categories as I write this, ensuring that you will never go hungry.

Conclusion

Those are the top 10 Facebook applications that for utility. Which apps did we skip that you think should be in the top 10? Which apps shouldn't be on our list? Please let us know in the comments. And be sure to check back in tomorrow for part 5 of our list. Let the debate begin!