Archive.org is good for making backups of news stories and other web pages but it doesn't save PDF files if I give it a direct link to the PDF file. It get a "404 not found" message. Is there a service that will save PDF files online? I'd prefer something where I can tag each site to find it easily later on.

There are various Firefox plugins which do this but it only saves to one PC. One is Scrapbook Plus. But I am looking for an online solution.

• Zotero.org saves web pages and PDF files and is intended to be used as a bibliography, with tags for searching, a Firefox plugin, and everything. But the free account limits storage to about 100mb I think.
• Google Drive and Dropbox don't have tags for files.