The web search engine Google has quietly started placing a counter on its home page to help people keep track of how much they use the service.

Most Google users do not have it, but a select few have a no-frills counter that notes the number of searches they have completed.

Google says the counter is just a test, and compares it to airlines tracking frequent flyers. However, some privacy experts are worried the counter could be used to spy on users.

The counter is placed on computer hard drives by a cookie, a software file that a website places without the recipient's permission or notification and that transmits information back to the site. "If the number contains more than three digits," the counter notes, "you truly are a Google frequent searcher".

Google, which processes about 200 million searches a day for free, said the counter had been placed on the hard drives of fewer than 1 per cent of its users.

Not on mine (although there's a BLOGGER button on the downloadable google toolbar). Are you one of the illustrious one percent?

(Y'know, I'm a little disappointed, really.)