This takes a while to explain, so let's see what I can get with this one.
First off, here's what the exploit does (I'll explain how to do it later): It's been discovered that you can set a bookmark inside any planet, moon or sun. There's a barrier around each cellestial body that's about 100km wide that keeps you from running into the body, but if you set a bookmark in the middle, you can still move within the body. This also allows for some outrageous tactical maneuvering, which I'll explain later as well.
Here's how to do this. First you have to warp to a planet, moon or star (the larger the body, the longer this process takes, so it's best to do it with moons, since they are the smallest bodies. We'll use moons for this example). Next you must traverse to the other side of the moon and get to where a stargate/station/belt is on the other side, putting the exact middle of the moon between you and said stargate/station/belt. Bookmark this spot on the other side of the moon as something like "outside [name of moon]" or something of your choice. Open your People & Places/Bookmarks window and get ready to hit the "Place Bookmark" button. Next, warp to the stargate/station/belt on the other side of the moon. You should warp right through the middle of the moon (as expected), but once you are inside of it, push the "Place Bookmark" button. Name this bookmark "inside [name of moon]."
This can be a bit tricky at first, but that's what the "outside" bookmark was for. If you warp to your "inside" bookmark and it doesn't work or your ship is shot off into a random direction, then just warp to your "outside" bookmark and try again until you get it right. The key is to warp to the inside of the moon and be able to move about within it. If you haven't figured it out yet, it's best to do this little trick with a really fast frigate; it took me close to an hour to do it with an Executioner going about 5.1 km/sec.
It's always good to remember the name of the moon you're inside. Once you get into the moon and are able to move about freely, press the alt button and look for the moon symbol which represents the moon you're in. This is where the fun part comes in, hehe. It should say that the moon is "0 km" away, that's because you're inside of it. Start moving towards the moon symbol, placing bookmarks every 10 seconds or so. Besure to name the bookmarks in asceding order "1...2...3...4...5..." etc. Eventually (once you reach the EXACT middle of the moon), you will shoot off in a totally random direction, going about 500,000 km/sec (yes, 500,000 km/sec! No, not warp drive, either) and you will steadily slow down. You'll end up really far away from the moon in the middle of nowhere. take all those bookmarks you placed and delete ALL of the ones except the next to the last one.
Let's say you got 5 bookmarks total before you were shot off: delete the "outside, inside, 1, 2, 3 and 5" bookmarks, keep #4. The reason you don't want to keep the last one is because it may be too close to the middle, then when you warp to it, you'll be shot off to the outside of the moon. Last moon I SS-ed, I got about 50 bookmarks before I reached the middle, so yeh, it can take a while.
This little trick has helped out my corp so much. We have these little spots set up everywhere. When someone's chasing us, it makes it seem like we're warping to a moon. When they get there, *poof* we're gone! When they get smart and probe us, they'll see we're 0 km away from a moon (wtf?). When they warp too us inside, we move to the middle of the moon and get shot off over 350,000 km away in a random direction, so if they do the same, not only will their gang be split up, but they'll have a 1 in 1 billion chance of ending up within range of any of us. Besides, you go so fast when you hit the middle of the moon that you literally dissapear. Makes for a great magic trick to show your friends!
Some of the corp members go out in groups and use drones to make these spots, I prefer the long way, heh. Sorry, it's very hard to explain, but hopefully I can get this exploit confirmed so I can get my account back to premium again.