One of the beauties of the Firefox Web browser is that it's possible to tinker with it, customise it, and use it as the basis for effectively a different product altogether. That's what the team behind Flock has done, as they've customised the browser to be one for regular users of social networking services.

As such, when you install the relatively slimline package and load the browser for the first time, you're presented with a far more cluttered layout than you're probably used to seeing. In fact, there's a fair argument that there's a bit too much clutter here, as the initial layout can be confusing.

Still, it doesn't take long before you're up and running, and what Flock immediately presents you with is links to some of the most common social networking sites on the planet. These range from Facebook and Twitter through to YouTube and Photobucket, while next to that is a list of your favourite feeds waiting to be populated (by default it's full of American news and sports sites), and next to that again is a Favourite Media panel.

This all forms part of the My World window, and should you log into a social networking site, a list of your friends can then be added to the left-hand side of the screen.

Flock is still a Firefox browser, just with some added functionality built on top of it. A big star button, for instance, adds a site to your Favourites, while media streams run on top of the browsing window (to hold, for instance, fresh pictures from your Facebook friends). Another useful feature is that there's an in-built Blog Editor, to help you compose and format a post before sending it live.

It all works really quite intuitively and, what's more, it's all very easy to customise. You can integrate social networking accounts and services easily enough, and the browser organises things effectively. It's also crammed full of take-it-or-leave-it little features that are fun to explore.

How much you get out of it, though, depends on a couple of things. Firstly, if you're a social networking addict and don't mind putting in a bit of time to input details of all your accounts, then you're clearly going to benefit. And also, if you don't mind moving away from the relative cleanliness of Firefox to a more crowded offspring, that too is in Flock's favour.

For while Flock does add features, and has a few tricks up its sleeve, our inclination is to run Firefox as our default browser and to move over to Flock for social networking duties. Fortunately, given that both are free, that hardly poses a problem.

A useful and interesting twist on the Firefox browser. Spend some time with it, and have a bit of patience, and chances are you'll like what you get out of it. It's probably best used as a second browser specifically for social networking sites, though.