Hi Chris, I recently transfered my main hard drive to a bigger one, I used "SuperDuper" which is a restore/recovery/clone program and is recommended, particularly if you wish to change a main drive. The resultant replacement was 4.75 Gb
smaller than the original. I regularly use, TechTool Pro, Onyx, Cocktail, Disk Utility and other programs to clean up and optimize. The advantage of Applejack is that it works at the basic UNIX level and replaces all the above. Also although the OS is meant to do its own cleaning and repair work - it actually doesn't do a complete job. You will find for one thing that the Virtual Memory Cache is rarely fully cleared out - I think Onyx is the only utility that even attempts it.
Do have a look at Super Duper as well it can be very useful.
Here is the LINK:
http://www.shirt-pocket.com/SuperDup...scription.html
Regards
Andy