HeinOnline has added a new feature: it is now possible to download PDFs of articles directly into your Dropbox account.
In the search results, click on the new icon Save to dropbox. You will be asked to log in to your Dropbox account and select the folder where you want to save the file.
The Save to Dropbox option is also available when viewing an article. Click on the PDF icon in the top bar to view the Print/Download options and choose Save to Dropbox in the next screen: