I read recently the original Apollo 11 press release and it mentions that the Saturn V's third stage (used for Trans-Lunar Injection) was deployed into a solar orbit of some kind:
I know that on other Apollo missions the third stage was crashed into the Moon ahead of the lunar module's landing to trigger the seismometers left behind by previous missions. Which Apollo flights did this and which ones sent their third stages to wander the solar system? For the ones that went into solar orbits, how well were those orbits measured? Do we know where they are now?