According to Andrew Michael, Livedrive's CEO, the Livedrive Backup service is almost invisible, and runs in the background on the users' PC hooked up to the internet.

In addition to keeping a copy of files online, the backup service allows users to access their files online and download them on a local drive at any time.

Unlike other backup services, Livedrive works in the background, continuously backing up all data without disturbing the general use of the machine. Users need not schedule a time to backup their files, leave the machine on overnight, or even start backups manually.

"With Livedrive Backup, you just install it and you never need to worry about it ever again. You're never disturbed by a `When do you want to run backup?' prompt", said Michael.

"There's nothing to configure, nothing to check or run or schedule", he added.

Unusually, the Livedrive online backup service is said to be unlimited meaning that - in theory at least - users can back up their entire drives.

Livedrive is also releasing a package called Livedrive Backup & Briefcase.

This backup package includes all of the functionality of Livedrive Backup, but with the added benefits of Livedrive Briefcase - an advanced access-anywhere service that allows web-based access to the backed-up files as and when needed.

Livedrive said Briefcase users can view or edit their Office documents, play their music, watch their videos and view and touch up their photos from a normal browser.

And in a service that sounds like Google's Googledocs facility, Livedrive said its Briefcase service can even be installed on multiple PCs, allowing users to see the same files on every PC they work on.

Launched in the US and now available in the UK, Livedrive says its service now has around 300 000 paying customers.