Alright, control freaks (otherwise known as "my people"), this one's for you. FolderSync is a fantastic little app we've just discovered that lets users sync folders between local storage and a number of online storage services. The app supports one- or two-way sync and provides a host of settings to tweak the app to all your sync needs.
Sync can be done on a schedule or when a folder changes. The user can also control how the app handles overwriting old files, whether to delete missing files, syncing of subfolders, and even to utilize MD5 checksums when syncing. The app works over 3G/4G, although this is disabled by default to preserve your precious geebees.