No, but it has been asked so many times, and it makes a lot of sense, so it's a safe bet that the feature will come one day.
Totally. I know how to with Dropbox but I'm sure that it's possible with every cloud service.
Once you've set a folder for cloud usage on Dropbox (ie a folder named "cloud items"), place your files inside it, then select and right click each, and click on "Copy Dropbox Link".
It will give you a link that's going to open the PDF on Dropbox' site. If you want the PDF to be downloaded instead, do the following:
When getting a Dropbox link, you get a link like this one:
Modfify it like this: (change 0 to 1)
OR like this: (change www.dropbox by dl.dropboxusercontent )