Orektic offers FTP Attachments, an ASP.net which allows you to store your attachments on your own storage instead of saving it on Salesforce.com® server providing cost and security Benefits.
FTP Attachments seamlessly integrates with the salesforce UI and offers a lot of benefits over native salesforce attachments. It provides cost benefit and a secure storage. FTP Attachments is available in two editions. Check out the FTP Attachments site for more details and to buy.