New details and features have surfaced about Rockstar's upcoming free roamer.

Following a special preview of the hugely anticipated Grand Theft Auto IV, many features and details have been spotted in the latest build of the game that aim to improve the gameplay experience, be they significant overhauls or subtle changes.

Firstly, for the first time in a GTA title, you will be able to take cover during gunfights. This feature is long overdue on one of the most influential free-roaming games, and will add an interesting way to handle hot situations - maybe even adding a tactical side to things in the heat of battle.

As well as a cover system, you will also be able to free aim while using firearms - however, those of you who get shaky fingers at the analogue sticks shouldn't worry as Rockstar Games has confirmed that the auto-aim system found in previous GTA instalments will be included in GTA IV.

Also, need to quickly around the block but have no wheels? Fret not - a brand new taxi system has been introduced. To call a taxi, you just whistle whenever a free taxi is available and you just direct your driver to where you need to go. It's interesting to note that you can only get a taxi to get to you if there's no passengers in the cab - meaning you won't get a guaranteed ride every time. This does, however let you experience the sights and highlights of the game's city location if you do manage to get a ridealong.

Another interesting feature found in this latest build is that your main character, Niko, can access the internet in-game. No, not actual internet. We don't know what sites Niko is allowed to surf but knowing the series' in-your-face humour, expect R* to invent some funny sites by release time.

Your in-game mobile phone will also play a bigger part than ever in GTA IV. As well as the usual phone calls you can call and receive for missions etc, you can also use your mobile to snap some photos and check important dates on your calendar. Bit of a to-do list in your game then.

Another tidbit of info is that your usual shop for weapons, Ammunation, will not be featured in this GTA. Instead, a chap called 'Little Jacob' will sell you your all-important weapons from the back of his car. Classy!

Moving on, there's been a significant change in how your character's health is managed. Firstly, there's no more heart circles to collect in the streets to boost your life. Regular rest and food will be the only two ways to restore Niko's life.

Finally, the default camera has been tweaked - this new angle allows players more room to get a better perspective of what the hell's going on!

More news on GTA IV as it appears.