OK, So i backed up my HD using Time Machine. Say that the HD on my computer crashed. What's the advantages and disadvantages of Time Machine as compared to say, Super Duper? Thanks.
SuperDuper will allow you to make a bootable backup of your system, Time Machine will not. To recover your system from a Time Machine drive you would need to reinstall Leopard on your new HDD and select the option to restore from Time Machine.
Although ultimately, if the OP restores from a SuperDuper disk image, if their computer originally had Leopard on it, they'll end up with Leopard again.
Until we actually see whether or not completely restoring a Mac from a Time Machine backup drive will work well or not, it's difficult to say Time Machine is going to be as reliable as SuperDuper! (which ALWAYS works, as long as no errors are reported). However, if it is as reliable as Apple makes it out to be, then there's no reason to use SuperDuper!, Time Machine just gives you so much more...