Caught on the hop again by Google's release of a desktop search tool, monster ISP AOL has jumped in promising that it too will offer desktop search through its version of Internet Explorer at some point soon.

A desktop search capability in a new browser is now in beta-testing, AOL promised, just one day after Google actually offered its tool for use. Perhaps unsurprisingly, AOL declined to provide more details about the desktop searching features. A cynic might think that this is because there aren't any.

Generally, desktop search applications index the content of PC hard drives to make them searchable. Traditionally such tools have done a poor job, which is why a variety of companies, seeing an opportunity, are entering the space to try to bring the advances attained in recent years in Internet search to the desktop.

Google unveiled a beta version of its desktop search tool late last week, and both Yahoo and Microsoft are expected to come out with offerings in this space. Other players in desktop search include Blinkx, Copernic and X1 Technologies.

Copernic also grabbed a few headlines by abusing Google's new tool as a danger to privacy - an easy fall-back position thanks to past concerns about what Google does with the information it receives. CEO David Burns said Copernic has looked at doing exactly what Google offers but decided against it because of privacy concerns - the keywords you type in to search your own hard drive are passed unencrypted over the Internet.

Copernic has decided it won't produce such a product, Burns said - but we have a strong suspicion these words will come back to haunt him.

Desktop searching is still in its early stages, however, and as such the leadership position is up for grabs. Searching needs to be equally easy on the desktop and the Web, without the user necessarily knowing which they are searching, said Charlene Li, a Forrester Research analyst. "There's still a long way to go, both for Web search and desktop search."