1. A computer-implemented method of calculating a bill for resource usage in an application hosting environment comprising: gathering resource information on each computer system resource of a set of computer system resources within a computer network, wherein said computer system resources in said set consist of memory resources, SAN resources, CPU resources, hard disk resources, network resources, and middleware resources; determining a cost per unit of resource for each said computer system resource in said computer network; gathering usage information on all computer system resources that have been utilized by at least one computer application during a billing period; determining, based on said usage information, a usage sum for each said resource utilized by said at least one application during the billing period, wherein said usage sum comprises a sum of all resource units utilized for each said resource during said billing period; determining a total usage cost for each said resource utilized by said at least one application, wherein said total usage cost for each resource is a product of said cost per unit and said usage sum; creating a dynamic usage bill based on a total charge, wherein said total charge is a sum of said total usage costs for all resources utilized by said at least one application during the billing period.