Safari has one, Firefox 3 almost had one, and the rumour is that Microsoft's Internet Explorer 8 is going to have one. Welcome to 'porn mode'.

It could have all kinds of sensible and laudable uses, but somehow we feel its use may be dominated by computer users covering their tracks from some of the muckier sites in the backwaters of the web.

Useful trademarks

On July 30th, Microsoft filed two trademarks. One related to "computer programs for deleting search history after accessing websites", while the second referred to "computer programs for disabling the history and file caching features of a web browser; and computer software for notifying a user of a web browser when others are tracking web use and for controlling the information others can access about such use."

It's been suggested that private browsing has its wholesome uses such as planning your partner's surprise party or hiding your Christmas shopping trail. And we are sure it will be.

We just feel that with all the distractions the feature would allow, the lucky recipients of all those parties and thoughtful gifts might just be in for a bigger surprise than normal.