Is there a way to tell Dropbox not to upload a certain file? (Eclipse related)

Question

I am trying to sync a code project between two computers, one running Windows and the other running Ubuntu 12.04. I use Eclipse on both machines, but the .metadata fold

Answer 1

Right click on the taskbar icon, select preferences, then the advanced tab and set up selective sync. Enabling advanced view will help, too.
In general, you should consider using a version control system like Subversion, Mercurial or git. You can make use of free hosting services (Assembla, Github, Bitbucket just to name a few) or set up a repository on a USB drive (works very well for personal projects).