I have KeePass2 installed on a USB flash drive. In Ubuntu 12.04 all I had to do to start is was right click KeePass.exe and select Open With Mono Runtime. In 13.04 I only have the options of opening with Archive Manager or Wine. I have mono installed and can start KeePass from the command line with either:
KeePass.exe
or
mono KeePass.exe
I can't start KeePass from a script on the flash drive because it is not possible to make it executable.