High speed metallic spheres flying by a stationary sphere.Afternoon jog, roughly 3-3:30 pm, late March, 2013.Sunny day, blue skies, scattered white puffy clouds.I am a GA pilot, always looking at the sky. I fortuitously noticed a reflective stationary sphere, silver or white, off towards the NE. I first thought it was a balloon, but the day was breezy, this thing was stationary, and was clearly not a balloon. Distance and size tough to assess, as there was no nearby object to serve as a basis for comparison. In any event, I observed the object for 10-15 minutes, and recorded three short video clips using my iphone. I knew it was not a balloon, but also knew that an iphone video clip of a stationary spherical object would not convince anyone otherwise, so I never planned to do anything with the video. Nonetheless, I shared the video clips with friends and family; this is where it gets interesting. My sister-in-law, who was not present at the sighting, noticed a streaking flash across the screen on one of the video clips. I uploaded the iphone video onto my computer, and viewed the video as close to frame by frame as I could (simpy hit play and then pause as quickly as I could). At the 27 second mark, you can see a clearly non-artifactual object (possibly up to four onjects) moving at an incredible speed from right to left across the screen. Not sure the speed, but it had to be several thousand miles an hr. The objects are not readily evident on the video in real time, other than as a terribly brief streak/flash on the video; the kind of thing one barely perceives. The best analogy is almost like the perception of very faint stars using one's peripheral vision; you know they are there, but you can't really get enough visual info to process the data.Incidentally, no noise whatsoever was heard.If desired, I can provide GPS coordinates and the video clip of interest.My backgound: I am a physician. I am also a GA pilot, and although no expert on aircraft identification, I know this was not a balloon, and I know these were aircraft unlike anything I have ever seen.FYI, I filed a sighting report and the video clips in April to MUFON. I am filing again simply because I don't see it in any database, and so I include it for the database.