This week's selection of iPhone applications will help you keep connected with what's happening on the popular microblogging site, Twitter. From letting your friends know you have taken a weekend trip to the country to retweeting the latest news headlines to posting links to pictures of your friend's drunken escapades, these applications will help you stay in touch in real-time.

The top five Twitter applications on your iPhone for the week:

Tweetie is a full blown Twitter application that is widely regarded as being the best Twitter application available on the iPhone platform. Along with the standard features of a iPhone Twitter client (such as tweeting, retweeting and sending direct messages), Tweetie provides users with access to multiple Twitter accounts, the ability to upload pictures in-app, location-based tweeting, automatic onboard link shrinking, access to Twitter trends, location-based search tools and an optional landscape keyboard. The application is quick to load and functional to use. Tweetie costs $2.99 in the US App store.
(Note: Tweetie 2 is just about to be released in the US as a separate application purchase, so if you can wait a few weeks it will save you from paying for and downloading both versions).

Twittelator Pro
Twittelator Pro is a heavy-duty Twitter application for users that can't even go to the toilet without letting their followers know where they are (pictures, video and maps included). All the usual options are there like tweeting, retweeting, trends, search and direct messages. Added functionality means that users can customize the application with a range of different skins, find new people to follow using the "Find Great Groups" and "Search Groups/Tweeters" tool, browse tweets by theme or location, tweet in landscape mode and add audio, video, maps and photos from within the application. There is also the option to create and save tweet drafts when there is no reception or WiFi connection. Twittelator Pro is priced at $4.99 in the US App store.

Twitterific is a beautiful-looking Twitter application that makes Tweeting from your iPhone look good. Posts from followers, replies and direct messages are colour coded and appear in the main feed. If you are a heavy Twitter user you can also log in with multiple accounts and filter tweets by reply, private messages or following lists. The new version of the applications enables users to post photos and sounds and to view videos from within the application. Tweets are stored on the device so you can keep reading even if you loose your phone signal. Twitterific is free in the US App store.

Echofon (formally Twitterfon)
Echofon provides users with a minimalist approach to Tweeting. Tweets are fast-loading and information is presented in an uncluttered, easy-to-read and understand format. The application enables users to keep up to date with the world of Twitter. Users can create tweets, reply to friends, update their location and post photos and video to Twitter from within the app. There are also basic search tools and a list of Twitter's trending topics. Echofon is free in the US App store.

TweetDeck is the mobile version of the popular Twitter desk client of the same name. The application supports multiple accounts and lets you manage and create groups from within the app. TweetDeck is organised into columns - one is dedicated to showing all feeds and updates from all your friends and one contains any mentions of your name(s). Users can add addition user-defined columns or sync their phone with their desktop client to replicate already-created filters on the PC. TweetDeck is free in the US App store.