You'd need a SD card formated ext2 or ext3 that has at least 500Mbytes of free space. It would probably be easiest to format the card and unpack the file on another computer running linux, but everything can be done on the N800. There are various articles that explain how to do that and I can provide pointers. The only other thing is the gzipped environment is 90Mbytes. Any ideas where I could post it?