THE recent attack on the Internet by the Slammer virus has shown just how open the web is to these sorts of problems. Fortunately Slammer needed database software to operate that many home machines would not be running, but it still slowed down the Internet for two days.

But as the use of broadband increases this leaves your computer open to hackers, who could use your machine to launch similar attacks.

For most home users on a dial-up connection there's little risk, but for anyone using an "always-on" broadband connection, things are different.

If your computer is permanently connected, the chances are that, sooner or later, an attempt will be made to access it without your knowledge.

That's why it's essential to get hold of some kind of a firewall program.

Just like anti-virus software, firewalls are fast becoming the must-have piece of software for anyone who wants to keep their computer secure.

You can pay money (in some cases, a great deal of it) for firewall protection, or you can do it for free.

The free options are perfectly good enough for the average home user.

Windows users should try Kerio Personal Firewall, available from www.kerio.com. An alternative for Windows is Sygate, at soho.sygate.com.

THE Shuttle disaster has shaken NASA (spaceflight.nasa.gov) to the core. NASA's site features all the latest news on the investigation.

There are also some poignant pictures of the Columbia crew during training and in-flight, as well as images from the memorial services held in the USA.

But there was a dark side to the news of the crash when alleged pieces of the Shuttle were put on e-bay, the auction website, to be sold.

E-bay has said it is monitoring the site to make sure no one tries to put items online. However, this has not stopped people putting legitimate pieces of memorabilia on the site such as photographs and badges, with some selling for over 100 dollars.

QUICK look at some of the more interesting sites includes a guide to the location of speed cameras in the UK.

The site (www.speedcamerasuk.com) has over 2,000 locations and a guide explaining how speed cameras are used in the UK. If you spot one that is not featured you can send it in to be added to the site.