Hmmm well if I started from here, picked a direction and began travelling, the most distant point I could travel to directly is... ...here.

On earth: The length of the Equator (...) is 40,075,016.686 metres (131,479,713.54 ft) in WGS-84 and 40,075,035.535 metres (131,479,775.38 ft) in IAU-1976 and IAU-2000. Otherwise google for "how big is the universe" :))

In Chinese culture，the furthest distance is the distance between hearts of two people. 世上最远的距离是心的距离。

Furthest distance from what?! Which planet? Confucius once said: He who want good answer must ask good question. :P Ok, he didn't really say that, but you get my point. :P

Ha, ha I think that it's probably Australia to the Artic