Small white changing object seen flying curving path in blue sky. Object seen straight overhead -followed to horizon. 6:14pm ArkansasMy wife and I arrived home from work between 6:11 and 6:14 PM (Central) I looked into the sky straight up and slightly northeast. I saw a commercial air plane flying East at high altitude. The plane was leaving a dissapating contrail.I saw a very white object that I first thought was a lone white crane (bird). I thought it was this type of bird because it was so white. The sun was obviously upon it. At first sight it also seemed to be 'flapping'.I have to rule out this object as a bird. Due to several reasons: 1. The 'flapping' was very irregular. 2. The 'bird' reached the far horizon in 60 seconds. 3. It was still visible through the haze of the horizon, towards the sun. (No bird could reflect that much light.) 3. The speed it reached the horizon combined with its altitude. 4. Odd pattern of flight.I rule out an aircraft. 1. No contrail. 2. Obviously different when compared to the airliner we saw at the same moment in the sky. 3. Path of flight was SE with several fairly rapid curves more easterly then more southerly then back to the SE. 4. The speed of the object. 5. The apparent 'flapping' which now can only be described as 'shape changing' as it went into the horizon.I rule out a satelite in orbit, or the space station, or space shuttle. 1. The sky was still blue and the sun shining. Only something the size of the current space station could have reflected so much light. 2. The path of flight was not a staight line. 3. The space shuttles have been grounded for months.Across the street from me two spanish speaking gentlemen also witnessed the object. From their angle they could see it flying into the horizon and farther south for 10-15 seconds longer than I could.