Thanks a lot, Helmuth!
I thought that that tool was for building Python apps only... but it seems to work for mine also!

I'm now in the repo! http://maemo.org/packages/view/backupmenu/
Note: Wait for the 0.30-2 version. 0.30-1 has the 'bootmenu-n900' dependency incorrectly marked as 'bootloader-n900'.