Unzip what just an example of a package. That is all. By harddrive, do you mean a random harddrive (on a desktop for instance) or are you referring to the eMMC (internal SD card) in the N900? I suppose you could even simply save the files to a microSD card. Yeah so when you install packages they are first downloaded by the package manager and saved to the location /var/cache/apt/archives/ temporarily before they are installed. They aren't deleted from the location usually unless you delete them manually or with autoclean (or similar). Anyway, you can just go ahead and copy them to your sd card (I'm not sure where it's mounted in your case; I'm an N810 user and not too familiar with the N900; my suggestions are generic debian-based instructions) # mkdir /media/mmc1/debz # cp /var/cache/apt/archives/*.deb /media/mmc1/debz/ might work for you but again I'm not sure that's the right mount point. Now if you want to be sure you are getting all the debian packages, you can be sure to # apt-get -d install foo # cp /var/cache/apt/archives/*.deb /media/mmc1/debz/ # apt-get install foo Hope that helps EDIT: For people that just want a list of installed packages (that way you can just go somewhere that has free wifi access and download all the packages in one shot after reflashing) Backup: foo=`dpkg -l | grep ii | awk '{ print $2 }'`; echo $foo > /media/mmc1/copymesomewheresafe Restore: bar=`cat /media/mmc1/copymesomewheresafe`; apt-get install $bar