As a few may have noticed, I've been watching Voyager episodes lately, and someone brought this to my attention. They say that Voyager is over 70,000 light years from the Alpha Quadrant, and Voyager is a vessel capable of sustained flight at Warp 9.975 (which is over 21,000 times the speed of light, or a light year every 25 minutes). So with that said, shouldn't the flight of Voyager back to the Alpha Quadrant take between 3 and 4 years, instead of 70 years like we're told?
Click on the link in my sig, and fast-forward the video to 7:58 for a comparison of warp speeds in TOS and VOY.
There is no "real" speed/time/distance table for Star Trek; the writers never used the ones in the technical manuals. The ships move at the speed of plot.
In "Balance of Terror" and "The Neutral Zone" the RNZ is so far from the Federation that communications take days to go back and forth from HQ. In the movie First Contact, not only do they get a live feed from the battle in Earth's solar system, but getting there takes only a tiny warp jump.