Extremly unusal aircraft observed in highspeed flight and hover during day light hours.During the summer of 1990 while traveling East on I10 outside of Winslow, Az I sited to my left (9 o'clock position) a formation flight of two aircraft with one aircraft trailing behind the left wing of the lead aircraft. Their speed appeared to be that of a jet military fighter aircraft, and on first observation thought - great- two F-14-s or what ever. The aircraft were headed South and after crossing over the Interstate they abruptly went to a hover. I was closing quickly on the stationary aircraft and then observered a third aircraft to my left traveling South, by this time I was within less than two miles from the two hovering aircraft. The third aircraft came into the formation with the other aircraft remaining stationary in a very abrupt manner, similer to what would be called hot rodding if a helicopter pilot did this. The aircraft remained in hover together for atleast a minute or two before rapidly accelerating and departing out of to the South in level flight. Would judge their altitude to of been at about 500 to 700 feet.The craft appeared to all be the same, however the aircraft who entered the formation is the one aircaft I focused my attention on. In general shape it appeared to be simlar to the aircraft Dick Rutan is building to go into outer space, but that is where it ends. The craft was a delta/flying winged aircraft with winglets or vertical stabilizers on the outside of the wings, the nasel (nose) of the craft was rounded and the empenage (tail section) appeared to have a slight down wash. Upto this point all seemed normal, but where a normal F117 or other aircraft would have a cockpit canopy an oval shaped tower was located at 90 degrees to the rest of the plane - simlar to the command bridge on a submarine. The surface of this tower was porouse, looking like you skin does under a microscope. It was curved over at the top as if the center might be open or accessible to enter or whatever. This tower had three colours ringing it horizontally, they were flat gray, black, and a magenta (maroon), appeared to blend into each other with no clear division of the clours.Everything seemed normal aerodynamicaly for a high performance plane except for this unusal tower sticking up (i.e. immense drag etc.). The rest of the aircraft appeared to be a light gray along the lines of what some Air Force planes are painted.Have not came forward with this at the time of siting because I thought just possibly the craft could be of this world and felt it not my place to disclose any advance craft of our nation. However, it has now been about 13 years and I've sure not heard of any such craft in our military inventory as of late.In closing, I am a retired soldier (22 yrs.) who worked in intelligence and hold a commercial aircraft license airplane single, multi-engine land with instrument and CFI. I seek no attention from this, but only wonder any other folks might have seen similar aircraft.((NUFORC Note: Date is approximate. PD))