Backing Up files

My situation

I have a macbook pro with a 200gb Hard drive and a 500GB USB hard drive. All the data that I have is over 200gb and so it will not all fit on my laptop and im using my USB hard drive as overflow space for the files that will not fit on my macbook.

What I want to do
I also want to back up all the important files I have on my macbook onto this USB hard drive, but only my music, video's, work and picture files, im not worried about anything els.

What im currently doing is partitioning my 500GB USB Hard drive to 1 200gb space and another 300gb space.. Im going to be using the 200gb space to back up what I have on my macbook pro and then use the other 300gb partition as the overlfow space for my files.

I'm after software that will automatically copy and back up the files on my macbook pro's hard drive to the 200GB drive. I only want selected files to backup and sync to this USB partition and so im thinking that time machine is not for me? Can anyone recommend any good free software that will do this job for me or a way to do it?

Prehaps there would be a better way for me to go about doing this?

Thanks

One suggestion. Would you be willing to consider upgrading the hard disk in your MBP? There has been an active thread in the Notebooks sub forum recently on a new 500 GB drive (from Samsung I think) that is MBP compatible. You could purchase the drive and then take your machine and the drive into your nearest Apple Store and have them do the upgrade. If you are skilled technically, you could even do the upgrade yourself.

This would give you the extra space you need, right on your MBP. I am thinking of doing this very thing myself, although in my case, I am looking for higher performance, not larger capacity, in the new disk I upgrade to.

Is a hard disk upgrade an option for you? The drive plus the installation would likely set you back about $350.00.

I never thought of doing this, and possibly in the future I will thanks for pointing that out! at the moment im going to give that option a miss though. Im just looking for software that will backup selected files to my hard drive.

I have set up automator to just copy over selected files to back them up but the problem with this is that I have to initiate the backup myself and it will copy all the files over and not just the ones that have changed.