I would like to have the Downloads folder of my Mac shared between two Macs using Dropbox. The idea is to have the same archives in both Download folders.
How can I accomplish this?
I would probably be simpler in the long run - if a little tedious depending on how many apps might use that Downloads folder - to set your Dropbox folder to be your download destination, rather than trying to persuade Dropbox to use another folder.
For Safari, set it in Prefs > General. Click download location, select other & navigate to your Dropbox folder.
You would have to do the same for any other apps that would use your standard downloads folder - but I'm certain it would be easier than trying to persuade Dropbox to use your original Downloads folder as its shared location.
I'm sure the alternative would be to make a symlink from Dropbox to Downloads, but I'm just not convinced it would be simpler to maintain.
Since many processes write to downloads (AirDrop, Safari, others) and Dropbox doesn't have a feature to pull an arbitrary folder into the sync domain, I would get a tool like Hazel to make folder actions to move anything that enters your actual ~/Downloads folder and moves the files to your Dropbox nominated Downloads folder.
You can automate this using the Automator app for free, but Hazel is so cool, I like to recommend it since once you start automating things like this, the options to be more efficient are much higher with Hazel and the integrations it makes easier than Automator does.
Use a symlink or a hardlink to the downloads folder from within the dropbox. You can use the Terminal or if you are less technically saavy or uncomfortable there are tools to do this. http://www.dropboxwiki.com/tips-and-tricks/sync-other-folders