Is there a cloning software that would also update the cloned HDD ?

I have dual boot XP & vista HDD.

I would like to clone that drive & then do incremental back up of it during the day while I am working on my system so in case of a crash, I will have the cloned drive ready to switch & my work is not interrupted & I am ready to go in few minutes.

I have cloned my HDD using Acronis but then it will not keep updating during the day as new data comes in.

Has anybody done this ?

Backups usually require restoring an image & with 500 GB data, it is a painful & time consuming experience.

Is there a software that will do what I want ?

Has anybody done this ?

Please help.

Thank You.