Originally Posted by Qtx

Nandroid backups which are a backup of your entire phone are fairly big. If you are a tinkerer and like flashing alternative roms, these all take up a lot of space. Titanium backup also does a backup of my apps to the card every night as well as uploading a copy to dropbox. Two copies is better than one right?

Also have a few different versions of linux running on my phone. They work a bit like vmware/virtual box type images so take up a fair amount of space.

Also log network traffic with the phone (wireshark) and over time the logs can take up space too.

Oh and there is some videos and piccys on there too!