Sync between Mac & PC version control system
I was facing the same question a while ago, and I decided against a solution based on Dropbox or similar tools.

Take a look at https://bitbucket.org/ - they offer free private Git repositories.

If you don't mind hosting your stuff on a public repo, you could also use GitHub, but if it has to be private, check out BitBucket. This is a real Git host, so you can pull/push, even if your machines are on different networks.

Dropbox always sounded like the wrong way for this. It can certainly work, but why do it like this when you can use a real Git host for free?