Pump it up
I've found that an electric soccer ball or basketball pump is excellent for cleaning a digital camera sensor. It blows a strong, constant blast, and its metal needle lets you aim the output with some precision. Moreover, because the needle is small, you can get it into cramped corners. Your best, though not cheapest, choice might be the Airman Cordless Multi-Purpose Air pump [ActiveTool USA, Inc.], which is handheld and supereasy to transport. It goes for about $35 at store.yahoo.com/satorsoccer/airman.html.