· If you are planning on committing, or being accused of, a newsworthy crime at any point in the future, don't set up a profile on any site. Us muck-raking journalists will be all over it before anyone has even raised your bail.
· Remember that it is quite common for potential employers to look you up on social networking sites to see if you are really the sophisticated professional you created for the purposes of your CV. I recently looked up a work-experience person on Facebook: he was naked in his profile picture. You know who you are.
· Remember that there are certain things you cannot ever change in your personal profile after you sign up. Why, for instance, did I ever think it was a good idea to call myself Piddophile on MySpace?
· If you're going to decline someone's offer of friendship, especially on Facebook, where it is rare for random people to get in touch, don't write back saying, "Do I know you?????" You have probably slept with them. Just ignore them and hope they go away.
· Politicians: if you need to put up a Facebook or MySpace profile to promote your policies, you are screwed.
· Don't invite work colleagues into your online life. Remember that old friends throwing about playground nicknames or recalling that time you wet yourself on the school bus may not seem so funny in a work context.
· Don't start sending messages or comments via Facebook or MySpace to people with whom you previously corresponded by email. That extra click or two to read your one-line witticisms is annoying.
· Remember that work IT departments see everything
· Another Facebook one: don't discuss private things on public walls. And it's bad form to flirt on other people's walls too.
· If you split up with someone with whom you are also friends on MySpace, don't remove them from your "Top Friends" section. It hurts.
· Never, ever, look up exes on any social-networking sites. That hurts, too.
Helen Pidd