I'm starting to like the Dropbox service. This is exactly what I wanted... If I change a file on my laptop at home I want it synchronize in the background to an online storage so it's available from anywhere. And, when I get to work, I want the file downloaded and waiting to be used.
There has to be a central repository and that is best to be kept online. With the availability of internet access nowadays, this should be very feasible. If you have to be offline, the file can be kept on whatever device you have. Once back to civilization, the file will be synchronized again.Dropbox - Home - Secure backup, sync and sharing made easy.
I also love the services that transfer only the changed parts of a file. That's somehow cool and exactly how it should be done. This probably won't work for encrypted files but that's alright. Security can be done in another way, encrypting the whole partition or creating a virtual encrypted disk with TrueCrypt.
So, even though I don't like reorganizing my files to fit into DropBox current limit of sharing only one folder at a certain place (My Dropbox) I'm willing to do that over time. I can set the offline sync to reorganize files for me. There will be more sync pairs but that's alright. Excluding certain files/folders in one set and including them in another, so that they sync to a different place, will not be such a problem.
I still have not decided whether to use SyncToy or continue using Unison. Unison is better at the moment as it has direct file-copy sync and sync via network, where it uses rsync to transfer only the changed parts. At the same time it is not actively developed while SyncToy is. This means that SyncToy might get all these features sometimes in the future.
Thinking of it... I might start using SyncToy more *after* it gets these features. :D Still undecided. Unison only synchronizes while SyncToy has Echo option, which I prefer sometimes, since I use certain folder pairs for backup not synchronization.