I found this really wonderful RSS feed which will calculate the number of stars encompassed in your own personal light cone.
From the link:
From the moment of my birth, light [that I could have influenced] has been expanding around the Earth and light [which could influence me, from an increasing distance of origin] reaching it -- this ever-growing sphere of potential causality is my light cone.
My lightcone contains 32 stars the most recent being P Eridani.