What I assume you're asking is if its possible to add games from your PC directly to a USB drive from Ubuntu, and yes this is quite possible (infact the original wbfs tool was only for linux)
There is a wbfs wrapper out there (GUI) but its not nearly as fully functional as the Windows ones, its easiest to use the command line.
The easiest thing to do is put the "wbfs" file in your /bin or /usr/bin directories
then from the command line type "sudo wbfs (command) (partition)"
for example, if I wanted to display a list of all games on my drive, I'd do "sudo wbfs ls /dev/sdc1" or to add a game "sudo wbfs add /path/to/iso/game.iso /dev/sdc1"
Partitioning is (in my opinion) far easier on Linux than Windows, when you install ubuntu run the updates/upgrade tool and then after you're fully updated install gparted (a partitioning tool) by running "sudo apt-get install gparted" and partition the drive how you want (fat32 for wbfs)
Then add your games, remove them, whatever you want. Someone posted earlier a GUI for this, but I'm not as much of a fan since its not as "developed" or whatever as the windows equivalents.
wbfs (put this file in your /bin folder)
http://www.mediafire.com/?c9tx4ljnmeb
edit: forgot to mention, the "dev/sdc1" will be different depending on which disk its assigned to and which partition. you can google to find out more about disk naming conventions in ubuntu.
