1. Do you use file syncing?
2. What do you use - program (SyncToy, SuperFlexible), service (foldershare, dropbox), or hardware (Raid 1) and across how many computers?
3. Do you prefer to have the data live only on your pc (foldershare) or in the cloud (dropbox, Live Mesh)?
4. Worth paying for?
5. Would you use it for backups? This is interesting to me because for most people, having an automated sync is a great backup strategy (compared to none), but then there are the dangers - i.e. deletes/bad data are also sync'd.
I think there is a lot of work being done in this area and a lot of scope to help make data easier to deal with for most people. As a developer I know the problem is non-trivial (multi-way sync resolution, transactional commits, differential syncs etc) yet to most users its a simple concept (keep 2 copies of my data).
Its an interesting space to watch.