Apple's Time Machine is the feature most Mac users are looking forward to when Mac OS X 10.5 Leopard is launched early next year.

A recent poll of Macworld UK Online readers revealed that 47 per cent think Time Machine, the ability to automatically back up data, sounds like the best new feature.

The first time an external drive is attached to a Mac running Mac OS X Leopard, Time Machine will ask if you’d like to back up to that drive. Set up the drive and Time Machine will run automatically in the background. Time Machine also allows you to change the drive or volume you’re backing up to, or back up to a Mac OS X server computer.

Of the 1,831 readers surveyed, 861 of them put Time Machine first, well ahead of: Spaces, with 222 votes and 12 per cent of the vote; '64-bit support', with 149 votes and 8 per cent; and Mail 3 & Group iCal, with 145 votes and 8 per cent. Last and least, Universal Access had just 22 votes at 1 per cent.

Widget creation tool Web Clip got 66 votes, 4 per cent of the vote, while Apple's Boot Camp, currently in Beta, received 137 votes, a total of 7 per cent of the over all vote.

Time Machine gained positive praise amongst readers but concerns about it hogging additional space on external hard drive were raised, along with questions about how you would back up your backup.

One reader queried: "Time Machine puts all your backed-up eggs into the one basket and that won't be acceptable to many users. I note that Apple say that if your Mac's hard drive fails, you put in a new one and then Time Machine will rebuild it to be exactly as it was when the last backup was made, a bit like Apple's Migration Assistant on steroids. That's a really great feature, but I wonder if there is also the ability to do a similar trick and duplicate the hard drive used by Time Machine."