Instructors and students who wish to use cloud compute cycles or services in their courses and/or research, have the opportunity to obtains grants and discounts through several provider prgrams.

Amazon logo Amazon offers educators, researchers, and students access to their Amazon Web Services through AWS in Education.
Google logo Google offers a number of resources for instructors and research faculty through their University Relations program.
Windows Azure logo Microsoft offers educators free Azure for use in classrooms and curriculum through Windows Azure in Education. And for those interested in using the Azure platform for research there's the Azure for Research grant program.