WARNING! You should not store your nvAlt notes on Dropbox if you plan to access them from multiple computers. Dropbox's file versioning can confuse nvAlt, causing data loss. If you want to use nvAlt from multiple computers, I recommend nvAlt's SimpleNote sync.
Issue #129: Notes being deleted from Dropbox while using NVAlt: https://github.com/ttscoff/nv/issues/129