An inexpensive way to share computing resources is the basic definition of cloud services. A company that has invested in computer power, and storage, and allows you to buy a small piece of that infrastructure for a monthly fee. Typically the monthly fee simply grows slightly as you use more of those resources. The awesome thing about Cloud Services is it allows you the benefit of the huge servers without your business footing the bill for the entire hardware bill.
Backup and drive and document sharing are two of the most prevalent Cloud Services at this time. Others that are available include hosted Microsoft Exchange, Sharepoint, and Terminal Services.