thanks for asking the question blackjackel ! I just installed SpringTomize 2 (for ios 5), because, as my 3gs is rebooting during calls ( :-( ), i want to put it back to virgin state (again :-( ), and don't want to do a restore from backup (that would restore my icon layout, but could also re-introduce files/settings that might cause the 3gs to reboot by itself).
So while looking for a solution to prevent me from having to do the whole apps-in-groups reordering again after the restore, i ran into Springtomize, but it doesn't say in the doc where it stores its backups (which the developer should add to the doc, as just saying the files are backupped is not enough)... It would be nice if it somehow would store it (in a Cydia-cloud) somewhere off the device, but at least thanks to ThHeartlessHero we now know from what location to backup some files... (for me i had to browse, using iExplorer, to root/private/var/mobile/Library/Springtomize/Layouts/ )