I was on a certain map, can't remember the name, but it was in space and had a planet near it.

You could shoot a graphling hook at the planet, and it would actually catch and take you towards it.

I'll try to find it again and post some screenshots

Maybe Facing Worlds? I know, that you can hook onto the asteroids. Kinda weird, but it works.

that's been fixed in the latest version of that map

Oh, well here is a link to the screenshot anyways
http://img509.imageshack.us/img509/3350/picture1yt1.png
It was actually a pretty cool thing to do, since it would be hard for someone to actually see you ;3