Digg.com founder Kevin Rose is at it again. And although it's capturing much of the limelight right now, it's not the only service of its kind. In fact, there are quite a few sites that let you search for other users or see who the top users are on Twitter. While some are quite useful, you probably won't be surprised to find out that not all are created equal.
TwitterCounter. TwitterCounter shows you your worldwide rank in terms of how many followers you have. The site includes a full list of the top 1,000 Twitterers, and regardless of whether you have 5 followers or 5,000, you can look up your own Twitter account to see how many people have added you in the past few days, how many you'll likely have in 30 days, and more. It's also a great spot to find folks you might not have known were on Twitter.
TwitterHolic. If you want all the functionality TwitterCounter provides, TwitterHolic probably isn't for you. Sure, you can search for yourself and others to see how many followers they have, and how many they've added over the past few months, but there isn't nearly as much in-depth data on the Twitter community at large. That said, it features the same list of 1,000 Twitter followers, and based on my testing it's just as accurate as TwitterCounter, which means follower counts are usually within 10 to 15 followers of the real figure. It's also a great place to find who the top Twitterers are.
WeFollow. It might be new, but WeFollow has already made an impression on the Twitter Community. The site groups together Twitter users and messages using hash tags--words that can be added to your Twitter messages and begin with an "#". Twitter users can update their stream with a tweet containing up to three hashtags they want to be included in and WeFollow adds their messages into the proper categories. The user list in each category is organized by the number of followers they have. I was generally impressed by the service and found that it's the best of the bunch, even though it's not as full-featured as I would have liked. But for directories, it's top-notch.
Just Tweet It. Just Tweet It is similar to WeFollow in that it asks users to add themselves to the directory listing that's relevant to them. Whether it's writing, movies, or genealogy, the site covers every conceivable topic and it's very easy to use. That said, there aren't nearly as many users on Just Tweet It as competitors like WeFollow and Twellow, so you won't find as many people worth following.
MediaOnTwitter. Though it's not the prettiest site in this roundup, MediaOnTwitter is a fine resource for those who want to find out which journalists, bloggers, and media outlets are on Twitter. I use it often, since it has the most comprehensive list of colleagues, and although ugly, it's easy to use thanks to the capability to search by location or name.
Social Brand Index. Social Brand Index is a listing of Twitter accounts held by public-facing companies. If you're looking for a more vertical directory of companies in topics like business and travel, this is a great place to start. While the site doesn't have every company listed in its directory, its strength is categorization. For example, its business section includes companies that are listed under commodity trading and direct selling.
TrackingTwitter. TrackingTwitter wants to be the definitive source for "brands, media, , celebrities, and electric artists." Anything outside of that and you'll need to use another directory service to find folks. It doesn't allow visitors to create sections, and it doesn't even allow you to add yourself. Because it's so focused, TrackingTwitter may not be all that useful for most people, since all those categories are already included in more general directories.
TweeterTags. Similar to WeFollow, you can find others on Twitter by using TweeterTags' keywords. But unlike WeFollow, you don't input tags. Instead, the service searches through Twitter to find commonly tweeted tags and allows you to click on them from a cloud. Whenever you click a tag, you're given a listing of people who have mentioned it in recent tweets. It's certainly not an exact science, but I found it useful for things like product names.
Twellow. Twellow is a directory of Twitter users that have been placed into categories based on their profile information. It's one of the ugliest sites in this roundup. But what it lacks in beauty, it makes up for in sheer size and availability of user profiles. In fact, the site has over 7,000 Twitter users categorized in sports and over 35,000 as authors and writers. Though huge, I don't find too much value in the idea of categorizing users into these subgroups. It's also not the fastest to update. Its "Latest Tweets" feature displays updates that are more than two days old and follower numbers were several days behind my actual count.
Twibs. A relatively new entrant into the directory space, Twibs offers an outstanding directory of businesses on Twitter. The site includes a featured section where you can find some of the more prominent businesses on Twitter. If you're looking for a specific firm, you can also use its alphabetical listing. It's the easiest (and best) way to find companies on Twitter.
TwitterLinkUp. Unlike its competitors, TwitterLinkUp requires you to sign up and input information beyond what's in your Twitter profile. Once complete (it takes about two minutes), you're placed into a "niche" category where people can find and follow you on Twitter. According to the site, it only has 150 members, which makes it one of the smallest community sites on this list. That said, it was more personalized than the other offerings, so it's worth a look if you want to do more than just submit your username to a directory.
TwitterVision. Twittervision uses the Google Maps API to show you where random tweets are coming from throughout the world. If you want a list of Twitter users divvied up by their interests, don't even consider using this site, but if you want to find people based on their location, it's fun to just sit back and watch.
I went to the site and was mesmerized by the tweets flashing on-screen from as close as New York (my home) all the way to Japan. The only problem is that when you click on a user's name, you're brought to their special Twittervision page, which means you'll need to go to search on Twitter to follow them. It's an extra step that became quite annoying after the allure of the Maps integration wore off.
Twubble. Twubble will analyze your follower list to find people who you might want to follow. You just give it your name and password and it does the rest. Twubble may not be a "directory" in the same sense as WeFollow or Just Tweet It, but it still helps you find people worth following. If you follow everyone who follows you like I do, it's tough to find Twubble useful. But if you don't, you'll definitely find folks you didn't know were on Twitter or people who are interesting enough to check out.
WhoShouldIFollow. A similar service to Twubble, WhoShouldIFollow allows you to input your username (without the password, unlike Twubble) and helps you find people who you don't follow. I found that it's more useful than Twubble and does a better job of finding relevant followees. Even better, it doesn't return people who you already follow.