Nah, too many unnecessary moving parts :-) If it's got to be in the filesystem let's stick it somewhere under /home/user (or even better /home/user/.osso so it gets backed up/restored automatically without additional configuration).

Hm, is there a GIOCondition that would notify for file creation? Maybe inotify could work instead, but either way adding an application-specific main loop callback inside a widget library seems dirty to me.