While there are a lot of things I like about Dropbox, one problem is its inability to synchronize limited files.
For instance, at my office I have a PC computer for which I would like to share frequently used reference files. Because Dropbox has an "all or nothing" structure, activating my account on that PC computer would force the synchronization of everything, including personal items that have no business on my office PC. Furthermore, tech staff, work colleagues, and even the cleaning staff have access to the office PC when I'm not around. For these reasons, I do not want my entire Dropbox library on the office PC. This may be a unique problem resulting from my own paranoia but I think not.*
I toyed with a number of possible solutions to this problem. One option is a MobileMe synchronization but again that opens the PC to other files and requires manual steps. I want this to be automatic. Another solution is to set up a free account with a different service such as Syncplicity or SugarSync. Of course that would require operating two synchronization services on my Mac and I'm not thrilled about two seperate applications tracking and syncing files and burning clock cycles.
The best solution I found was simply to set up an additional free 2 GB Dropbox account on the PC under a different e-mail and "share" a folder from my Mac-based paid Dropbox account with the new account. This allows me to control access of what gets synchronized, limits the ability of someone on my PC to only obtain access to the shared files, and allows me to avoid running two synchronization applications on the Mac. Problem solved, for now.
* I'm aware I could set up a limited synchronization using Sugar Sync. The problem is that those require you to submit your account information and would allow a prospective evildoer simply log into your web account and have access to the whole enchilada. See what I mean about paranoia?