Post by David Pierce. Find me on Twitter.

Many if not all experienced Twitter users use an application other than the Twitter web interface, and for good reason. TweetDeck’s my personal favorite; others use Twirhl, Tweetie, or any of a huge number of ways to manage your Twitter account.

But I’m not talking about those. Below are 25 applications that do something Twitter or the applications on which most of us use Twitter, don’t.

Some let you schedule your tweets, others let you see Twitter users near you. There’s a ton of functionality to be had from Twitter users and their tweets, and the classic Twitter interface doesn’t begin to touch it all – nothing does. Pick and choose among these 25, and you’ll find new friends, new tweets, and tons of useful functionality added to Twitter.

Twellow – Find Twitterers with similar interests to you, by searching through a yellow-pages interface.

NearbyTweets – Enter a zip code or city, and a distance, and you’ll find Twitterers and tweets from nearest where you are. Awesome for using Twitter to meet real people.

Twuffer – Schedule your tweets to be sent later, at a time you choose. Perfect for sending tweets for monthly reminders, or announcements.

Twitterfall – See tweets coming in a waterfall, in an easy-to-read way. Narrow them by tag or keyword, and see a real-time list of what people are talking about.

TweetMapper – Map your tweets and your friends’ tweets – awesome for finding out where things are going on.

TweetStats – Graphs of your tweets per hour, tweets per month, who you’re tweeting, and what programs you’re using to send your tweets.

TwtPoll – Create and distribute a simple poll over Twitter, which your tweeps can answer right from their Twitter accounts.

Post Like a Pirate – Takes whatever you’re typing, and turns it into Pirate-Speak, thus making you far more awesome. Available for Twitter, MySpace, or email.

TwitterAnalyzer – Google Analytics for Twitter. See who retweets you, how many people are seeing your messages, and how fast your Twitter follower numbers are growing. Great, in-depth analytics.

Twtcard – Create super-simple greeting cards specially designed for the Twitterer of your choice. Got a Twitcrush? This is a good way to declare your undying love.

Twtvite – Describe your event in 140 characters, use your Twitter friends to populate the attendee list, and plan your whole event using only Twitter.

RSSFriends – Create an RSS feed of people who follow or unfollow you,  so you can see exactly who is following you, and when.

TweepleRank – Finds the best people on Twitter to follow, based on #followfriday, #MrTweet, and #TweepleTuesday recommendations.

FriendorFollow – Find out who you’re following that isn’t following you, and vice-versa.

Twitterless – Find out who stops following you, as well as showing you your follower history over time. See where your followers are, who they are, and what they’re tweeting.

Tweetworks – Sorts Twitter into groups and discussions, creating conversations out of @replies for you to be a part of.

Listento.fm – Share videos, songs, or movies with easy links to tweet what you’re listening to or watching.

TweetScan – Searches Twitter, identi.ca and others, with constantly updated results available by email, RSS, and others.

TweetOClock – Want to know when the best time is to send someone a tweet? Plug in their username, and TweetOClock figures out when they’re most reachable.

Twt.fm – Login via Twitter to twt.fm, and enter an artist and song title. You’ll get a track page that you can put on your Twitter feed, and twt.fm automatically finds and plays the song for you.

TweetMeme – Tracks the most popular links on Twitter, by the number of times it’s retweeted. Tweetmeme also gives you a way to put a “Retweet This” button on your own blog.

TwtTrip – Use Twitter to plan your next trip. Meet other travelers, join local tweetups, and tweet from the road so all your friends can see what you’re up to.

Vlaag – Lets you see the most popular hashtags and topics on Twitter, with more popular tags in larger text. One click lets you read tweets on a given tag.

Annotated Links – Send a bunch of links, and a personal note, as one shortened link over Twitter.

TwitterSnooze – Quiet a few of your loudest Twitter friends by temporarily unfollowing them. Perfect for trying to catch up on your old tweets, letting you ignore the worst offenders.

What’s the coolest thing something else does that Twitter doesn’t? What do you wish you could do on Twitter?