Two aircraft looked like they were gonna collide and after passing there were 3 or 4.

At about 5:03pm today Feb 18, 2011, I looked up into the sky facing west and I saw 2 seemingly to me jet aircraft heading towards each other.  One was heading east and one was heading west.   The aircraft that had 4 vapor trails was heading east. The aircraft that was heading west had 2 vapor trails.
Both aircraft looked like they were heading for a collision when the east bound aircraft seemingly pulled up and appeared to have dropped something.  The west bound aircraft seemingly maintained its course and dropped something as well.  The aircraft that was heading east seemed to have accelerated significantly.
It appeared that both items dropped had vapor trails and started heading east.  My dad came outside and saw 3 aircraft’s vapor trails 2 heading west and one heading east.