Here's a useful site that showcases tools and technologies for assessing your infrastructure and optimizing costs. Poke around a bit and learn about optimizing server, branch, desktop, and virtualization architectures. For example, see the following best practices for desktop optimization:

PC Lifecycle Planning  

In addition, here are some tools to help:

  • Get started with free tools and guides for Desktop Infrastructure
  • Optimize Your Desktop Infrastructure
  • Desktop Optimization using Windows Vista and 2007 Office System
  • An Optimized Platform from the Datacenter to the Desktop