Q: Keep track of what is on USB Devices Is there any software that keeps track of the content of USB Devices I connect to my System? I have several (~15) USB-Sticks and I can't remember were I put certain files/pictures etc. Using Ubuntu 12.04 LTS 64bit.

A: Have a look at Gnome Catalog (package gnomecatalog)

A: git-annex is an excellent solution for command line users. It keeps track of where your files are across local filesystems, external drives, different computers and cloud storage providers. git-annex assistant is a friendly front-end to it, but is still in development.

A: If you like commandline tool try "mlocate".
It support file name search with "regular expression"
Using a switch you can specify custom database to search. This database can be created using updatedb.mlocate or updatedb (by specify location to index)
To cerate DB:
updatedb -l 0 -o db_file -U source_directory
Eg:updatedb -l 0 -o /tmp/boot.db -U /boot/ 
To search in the DB
mlocate -id db_file file_to_search
examples
Search for all files in DB boot.db
mlocate -id /tmp/boot.db .*

ubuntu@ubuntu:~$ mlocate -id /tmp/boot.db .*
  /boot/System.map-3.5.0-17-generic
  /boot/abi-3.5.0-17-generic
  /boot/config-3.5.0-17-generic
  /boot/memtest86+.bin
  /boot/memtest86+_multiboot.bin
  /boot/grub/gfxblacklist.txt
  ubuntu@ubuntu:~$ mlocate -id /tmp/boot.db -r .*
  mlocate: non-option arguments are not allowed with --regexp
  ubuntu@ubuntu:~$ mlocate -id /tmp/boot.db -r '.*'
  /boot
  /boot/System.map-3.5.0-17-generic
  /boot/abi-3.5.0-17-generic
  /boot/config-3.5.0-17-generic
  /boot/grub
  /boot/memtest86+.bin
  /boot/memtest86+_multiboot.bin
  /boot/grub/gfxblacklist.txt
  /boot/grub/grubenv
  ubuntu@ubuntu:~$ 

search for all files with extension .cfg using regular expression, ignore case
mlocate -i -d /tmp/boot.db -r '.*\.cfg$' 
(see man page for more info such as switch)
