UAVs have been under development since the beginning of flight. PBS NOVA's website has a very informative Chronology of UAV development. A comprehensive history of UAVs can be found on the Vectorsite.com UAV webpage. A review, by an unknown author, presents highlights of early UAV use. Excerpts from the Autonomous Vehicles - unmannedaircraft.com website include this historical perspective of VTOL and rotary wing UAV platforms. Finally, I highly recommend the book Unmanned Aviation: A Brief History of Unmanned Aerial Vehicles, by Nuke Newcome and published by the AIAA Press. Nuke has created an accurate historical context to view the development of UAVs starting with Nikola Tesla (remember the Tesla Coil in Colllege Science?), Elmer and Lawrence Sperry, Glenn Curtiss, Peter Hewitt in the early 1900's through WWI and II aerial torpedos, from Reginald Denny's Model Aviation Shop on Hollywood Noulevard leading to Denny's Radioplane Company becoming a prime military supplier, and pioneer Teledyne Ryan's aerial drones leading to the Pioneer, Hunter, Shadow, Heron, Predator, Global Hawk and X-47 airframes of today. Great stuff - well worth the money.
Armada International has published in March 2004 an interesting article "The Growing World of Unmanned Spies" looking at different UAS types and topics.
The development of UAV's specifically targeted for commercial use is fairly new in the US NAS. There have been a number of test bed systems and applications projects however, with the exception of a few research institutions, little information has been made publicly available on the success of these projects in terms of costs or technical success. UAV commercial application development is somewhat more advanced in both the European and Australian NAS.
In 2004 NASA published a UAV Capabilities Assessment in draft form (overview). A major revision is scheduled for 2006. This study is a comprehensive review of the potential use of UAVs for Civil Applications. The NASA URL for this study is here.
UAV use for commercial applications worldwide is beginning to gain traction. The Department of Transportation published the proceedings of a conference in 2003 laying out "UAV 2003:A Roadmap for Deploying Unmanned Aerial Vehicles (UAVs) in Transportation".
The future for commercial use of UAVs is ripe with opportunity, especially for platform vendors who have been less than successful in the military markets, and who are willing to modestly retool and to repurpose their platforms for commercial use. The industry is only awaiting regulatory certification for DSA collision avoidance and airworthiness standards for UAVs in civil missions to "take off".