At the time of writing, Wikipedia's list of notable social networking websites falls just short of the one hundred mark. If you're not signed up to at least one of them, it's probably only a matter of time - especially as more and more people seem to be adopting them as their preferred means of online communication.

Social networking sites may be a Naughties phenomenon, yet the first of their ilk actually appeared back in the mid-Nineties. However, only in recent years have they exploded in popularity, with market leaders MySpace, Facebook and Bebo drawing tens of thousands of new recruits each day. The benefits are obvious - you can keep up with your social circle, track down old acquaintances and make new friends to boot! And there are other good reasons to use them too - for instance, if you earn (or aspire to earn) your living as a musician, artist or filmmaker, refusing to embrace the free global publicity such sites can generate could be seen as pure madness.

But needless to say, for all the signing-up of accounts there's been a hefty backlash. Aside from worries that these sites are rife with stalkers and other unsavoury characters, there's the small issue of Newscorp and the like owning detailed maps of your habits (not to mention them making a huge pot of money along the way). Then there are concerns over identity theft, as people post increasingly sensitive personal data online, and there's also growing unease that employers, governments and even private investigators are trawling such sites in order to dig up dirt on users. Aside from all of that, don't they just encourage people to waste more time online than they already do? Is there really any point in sending someone a virtual vodka and coke, or throwing a virtual sheep at them?!

Are you a virtual social butterfly? Or do you cringe at the thought of airing your personal details to the world? We'd love to know...

• Are you a member of any social networking sites? If so, which ones - and when and why did you join them?

• Does the data collection element of such sites concern you?

• Are you surrounded by people at work who constant check their Facebook or MySpace account?

• What do you think about the 'proactive friend hunting' behaviour particularly prevalent on MySpace?

• Have you ever felt pressured to sign up to a social networking site? Or have you ever pressured someone else to do so?

• Do you know anyone whose online communication is done mainly through social networking sites?

• What other web technologies do you use to interact with online? Messaging? Chat? Forums? Blogs? Discussion groups?

• If you were to set up your own social networking site, what angle would it take? What would it be called and what special services would you offer?