How do you use Dropbox without the cruft?

Dropbox used to magically sync a folder across the web and show its status in the menu bar. Nowadays it's its own 400MB app which also syncs file.

I don't want that.

How can I continue using Dropbox the way it was ideated without having to deal with an app? Even a plain hourly/daily sync cronjob would be good enough for me.

Note: I need Dropbox specifically because some colleagues use it.