Which five apps rule the Facebook universe?

Earlier this May, Facebook launched an open application platform, enabling anyone to develop applications with the ability to access and use the social networking site's vast wealth of user data.

Less than two months later, everyone from big companies to regular Joes are building tiny apps and embedding them in users' profiles.

Some are stellar and some are stinkers, so we asked Wired News readers to vote for the Facebook apps they like the best. Here, in reverse order, are the results of our reader poll, along with our own take on each of the winners. You'll need to be logged in as a Facebook user to access the applications through the links below.

__ Calendar by 30 Boxes__

This offering from makers of the popular calendar web app 30 Boxes lets you manage all your Facebook-related dates right on your profile. Keep track of birthdays, concerts, assignments and other events relative to your online life, and share those events with your Facebook friends. If you're a 30 Boxes user, you can sync your calendars and add events either in Facebook or at the 30 Boxes site. But it also wins just because the clean, Ajax-powered interface makes for the coolest and easiest to use online calendar for Facebook.

__ iLike__

Track your musical tastes with this app from social-music-discovery site iLike. Once you add the app, you can add songs and videos from favorite bands to your profile page. Don't expect anything too avant garde – iLike is made for the mainstream. You can also list the concerts you plan to attend, which makes hooking up with friends at shows easier. But the real draw here is iLike's musical Challenge game. It starts playing a clip, and you have to identify the artist or the song title. Compete for points and show off your score. Is that Prince or Michael Jackson? "Skater Boi" or "Girlfriend"? The guessing game alone makes the app worth adding.

__ Where I've Been__

With Craig Ulliott's tiny app, you can put a map of the world on your profile and mark up the places you've lived or visited. Part travel diary and part bragging rights, the map is well-designed: Countries or states you've visited show up in blue. If you've lived there, the place is marked as red. If it's on your list of places you wish to visit, it's green.

__ Graffiti__

A Wired News reader favorite, and it's no wonder considering how dead simple this one is. Put Graffiti on your page and your friends can leave messages or draw pictures. Unlike other note-leaving apps, like Your Wall, Graffiti lets people be creative and colorful. One of your friends just might reveal herself to be the next Georgia O'Keefe.

__ Free Gifts__

As bizarre as it may sound, Free Gifts is an app that lets you send and receive gifts from friends. The gifts are worthless and silly – a panda bear, a pineapple, a roll of duct tape, a pink elephant in a business suit. But as creator Zachary Allia writes, "It's the thought that counts." Show the world how much your friends love you by displaying the last four gifts you received on your profile page.

__ Honesty Box__

Put an Honesty Box on your profile page and people can leave anonymous messages for you, anything from "You're dreamy" to "You have bad breath." Blue text means it's from a man, pink posts are from a woman – other than that, it's totally anonymous. The person leaving the note doesn't have to be signed in to Honesty Box or have it on their page. It's a whiteboard on your front door – a brutally eye-opening whiteboard.

Compiler: Facebook Becomes the Web's Plug-and-Play Application Platform

Private Facebook Pages Are Not So Private

Lessons From the Facebook Riots