Sure, they are out there. I doubt they've had the opportunity to visit us here (despite reports to the contrary!) but perhaps they've detected life on Earth by observing the water vapor bands, and perhaps even seen evidence for ozone in the water vapor window. Can we look back and find them? The search is on! Once great candidate is Sco 18. Sometimes called a "solar twin," Sco18 is a 6th magnitude star in the constellation Scorpius. Google it, and find pages like this one:
http://www.daviddarling.i...dia/A/18Scorpii.html
Could this solar twin star have an orbiting "Earth twin"? Might there be a twin of you or me (except for the pointy ears ;-) looking back in the telescope and wondering? It may become a testable hypothesis during your lifetime!
.Bob.