I’ve been testing out Dropbox as a way to sync my 1Password files between computers (which works really well) and, more experimentally, to share a single iTunes Library (which… doesn’t work so well).

A few days after installing it, I started getting “Your Startup Disk Is Almost Full” messages.  Having had a similar experience with a client who was backing up to Apple’s .MAC service, I quickly zeroed in on Dropbox as the culprit.  A quick bit of Google-Fu found other people having the same issue — and it also found a solution.

Dropbox creates a hidden folder in your home directory named “.dropbox” where it keeps a database of your account configuration and information about what should be synchronized to your local Dropbox folder.  Inside this folder is a “cache directory” which seems to accumulate a *TREMENDOUS* amount of data (mine was almost 10GB!).  The program currently doesn’t allow you to manage the size of the cache, so I had to manually clear it out to free up my hard drive space.

Since then, some enterprising Dropbox user has written a Dashboard widget to monitor the size of the cache and allow you to clear it out with the push of a button.

Download it here:

Dropbox Cache Cleaning Widget