You really dont want an air compressor like that just to clean your computer with unless you intend to get a nail gun too and do some home remodeling. An air compressor will cost you close to $200, a can of canned air from staples will cost you $5.
Or a small vacuum with several nozzles. <- Thats what I use.
EDIT: I find the term "Canned air" in the quoted post funny.