"Hi gb Travelling above escape velocity or orbital velocity isn't recommended - and 5 km/s is over twice the Moon's escape velocity. Problem is that you have to thrust towards the Moon to remain in a circular curve around it if you travel faster than the local orbital velocity - which, on the surface, is just 1.68 km/s. Thus the minimum trip time is ~x/1.68 km/s to anywhere unless you're wasting energy curving the path into a circle by applying a counter-thrust."

Ok. Yeah, I thought of mentioning it [and I have in the past] but I just wanted to add a brief comment regarding Paul's article and sort went too far as it was...
And also I didn't have the lunar orbital velocity in my head- shocking, no? :).

If lunar orbital speed is 1.68 km/sec, and it could a bit slower then this and requiring some rocket power for making sure you land in the precise location [sort of like a very high speed carrier landing] plus you could do a hop [as you could on earth with suborbital travel].
So it might be around say 1.5 km/sec or or just under an hour to travel roughly the farthest one can travel from one point of the moon to another.
And it could easily take more than an hour if you count from the time you get on and get off at your destination.

But anyways 1.68 km/sec would fastest one could go on the moon unless you "fly" along rails upside down [and we will skip the part about tunneling at significant depth below the lunar surface].
And similarly on Earth this speed limit would about 8 km/sec- you need to travel slower than this if suborbital or fly upside down on tracks to go faster.

So at 8km/sec on earth, the furthest point to point is about 42 min.
Of course on earth one has the 24 hour rotation and depending upon which direction you go it will add or subtract from your velocity- so going a further distance east rather than west could use less energy- though one could go faster west use more energy and get there in less time.

It's .46 km/sec + or - difference. So roughly at the equator east goes 7.54 Km/sec and west goes 8.46 km/sec. For distance of 20,000km east is 44.2 minutes and west is 39.4 minutes. Would anyone paid extra money to save 5 minutes by going west?
Oh, since I'm mentioning decimal points, the orbital speed at the surface of earth is more precisely: 7.905 km/sec [according to SMAD III table on the last page]

[One problem [and lots of others] with tracks could be earthquakes- a strong enough earthquake and 8 km/sec could make quite a mess.]