Anyway, decided to rent a 172 for some extra time and decided to file IFR to SPI from PWK. (wasn't IMC, but the altitude I wanted to fly at was supposed to have scattered clouds, so I wouldn't have to be cloud dodging.) Well, after departure, Chicago Departure vectored me out East and then down the heart of Chicago (flight visibility was less than 5 miles due to haze!) and while due east of ORD, had a 777 pass below me as they were departing from KORD about 2,000', directly below that is! That was really cool looking. They then vectored me directly overhead Meig's and at that moment I had an American Eagle RJ pass about 1 mile to my right heading the same direction, same altitude. About a minute later, a United Express RJ passed off my left, same altitude, about a mile over. Wish I had my camera with 300mm lens! Talk about some nice shots! Well, after that it was quiet until it came to depart SPI for PWK. While preflighting, I got to watch 2 F-16's from the Illinois ANG take off in formation. After that, I taxied into position to hold for departing traffic on the crossing runway and had 4 F-16's depart right in front of the windshield. I was going to bring my camera and forgot. Everytime I forget, I miss some spectacular photo opportunities!