All I have done is copied a differnet dashboard to the HDD of the xbox. There is no illegal sooftware on there. I did not want to do this to play copied games, but so I could use it as a media centre and enable 1080i on the xbox which you can not do with m$ dashboard.
There were no mod chips used. You basically just wait for the microsoft logo to appear and remove the data cable from the HDD and then the drive in unlocked. You connect it to your pc and the use a FATX program to copy stuff to the hdd.
Once this is done you put the drive back in the xbox and switch it off. Hey presto mediacentre xbox. Can even ftp to it now through the network connectio.
If discussing any of this is against the TOS and posting guidlines please feel free to moderate me. I think however that I am on safe ground.