ProjectSend (previously cFTP) is a clients-oriented file uploading utility. Clients are created and assigned a username and a password. Then you can upload as much files as you want under each account, with the ability to add a title and description to each one.
ProjectSend provides easy and secure multi-file uploading and unlimited file size on ANY server! Even on common hostings shared accounts. When the client logs in, he will see a web page that contains your company logo, and a sortable list of every file uploaded under his name, with description, time, date, etc. It also works as a history of "sent" files. They can check the differences between versions, the time that it took to do that, and so on.
Additional benefits include saving hundreds of mb. on email accounts since every file remains on your server until you decide to delete it, and they can be accessed from any browser anywhere.