This file allows you to calculate how long it would take to get to various celestial bodies based on some fixed speed expressed as a percentage of the speed of light in the vacuum.
It is reported that it took the Apollo astronauts about three days to get to the Moon (and obviously three days back). Assuming that the distance to the Moon for an Apollo mission was 240,000 miles, what was the average speed, in miles per hour, for the astronauts' journey to the Moon (and back)? Check you answer here.
Try setting your speed to the speed of light, and see how long it takes to get to the Moon, the Sun, Mars, etc.