The factory PhatBox is designed only to run using PhatNoise approved disks which have a special signature written onto them. Although they now ship out 120G disks, they cost the earth to buy.
The guys here have found a way to 'flash' the PhatBox so that ANY commercially suitable disk can be used with the PhatBox. Not only this, there are also workarounds for some of the plugins which are restricted for use with only one DMS. There is also a SIG hack available (but not released) which prevens the requirement of having many important files requiring their own 'Signature' file (.SIG)
These are the things that I know of (and I've only been around a year) - if there's more I'm sure others will chip in. However all of these things are encompassed within the term 'hack'.