Astronomy Software?

Hi all,
I am looking forward to getting a nice sized telescope sometime
in the not too distant future. But in the meantime, I would like to
enjoy the profound beauty of the Universe virtually, by way of my
very capable PC. Does anyone know of any good freeware astronomy
programs out there? Especially where one could sort of "fly" through
the stars, taking in the marvelous sites. Not so much just static pics
of astrological objects. Clear Skies!
C88