Airliners.net
(a huge collection of photos of all types of aircraft)

Airshow Action
(a great collection of pictures from many airshows - all types of aircraft)

Alex's Sailplane Directory
(pictures and stats on over 300 full-size sailplanes)

Arizona Models
(early and vintage flying scale kits, spoked wheels, instrument detail kits, vintage engine kits, even a set of Wright Flyer kits in various sizes)

Aviation Heritage, Inc.
(books, photo CD's, 3-view scale drawings and an online historical magazine)

Carter Copters L.L.C.
(an interesting full-size project, now with a few hours of flight test time completed, designed to result in a VTOL aircraft that can cruise at 400 MPH at 23,000 feet!).

Classic Rotors
(Rare and Vintage Helicopters)

Collings Foundation
(home of a great collection of aircraft and automobiles - right here in Massachusetts)

DefenseLink
(the home page of the U.S. Department of Defense, with links to other military sites and information sites)

Eduardo's Aircraft 3-Views

Ejection Seat Gallery
(yup, a site with technical specs, drawings and pictures of ejection seats of many well-known fighters!)

Elevon
(a treasure trove of aircraft information pages, photos and Joe Baugher's Military Aircraft Encyclopedia)

Gliders in Lithuania
(a site with lots of full-size sailplane pictures and articles on various topics - see the "index" button at the top for articles)

Helicopters History Site
(an interesting view of heli history, with info and pictures on many common and obscure helicopters)

HeliSpot
A huge collection of helicopter pictures, organized by manufacturer and model.

Lockheed Martin Aeronautical Systems

Monino Soviet Air Force Museum

National Museum of Naval Aviation

Rotorhub
(a global helicopter news site)

Sailplane Directory
(site with links to pictures and info of a large number of full-size sailplanes)

Scale Aero Web Magazine
("An E-Zine promoting the sport of flying scale modeling")

Scale Model Research
(Bob Banka's site)

Smithsonian/Paul E. Garber Preservation, Restoration and Storage Facility
(This is the facility that the National Air and Space Museum uses to preserve and store the air and spacecraft displayed at the museum. The Artifacts section has pictures of various projects, and there's even a live "web-cam".)

TLai Enterprises Modeling Fonts
(two Windows fonts you can use to make authentic stencils and lettering for U.S. Air Force and U.S. Navy models)

Totavia Aviation

U.S. Air Force Museum

U.S. Air Force Technology Site
(Net Resources Inc)

U.S. Army Technology Site
(Net Resources Inc)

U.S. Navy Technology Site
(Net Resources Inc)

Virtual Aviation Museum