Teleporter Coordinates: What's the secret?

I've used a free teleporter script (just your standard 250m sit-jumper) for months whenever I needed to install a porter somewhere. It gets you where you're going, but there always seem to be little problems. For example, sometimes when you reach your destination you're just left floating in the air when you should be standing on firm ground. Other times you'll get a 'Sit Canceled' message and your avatar will ricochet around the room for a couple seconds once you get there.

The first line in the script is a global variable where you set the destination coordinates. What I've always done is just to stand in the place where I want the porter to take me and write down my X, Y, Z coordinates as shown on the top of the screen. And like I said, this only seems to work as expected about half of the time.

I've experimented with placing a prim on the landing point and getting the exact coordinates (the numbers at the top of the screen are rounded), but this hasn't helped me either. (I was setting the prim at hip-height.)

What's the trick to setting porter coords? Should the height be lower or higher than desired? Should I offset the x/y numbers? Do the coordinates represent a certain height or location on my avatar?

To get the position I made up this little script. Just create a prim and flatten it. Put this script in, make it pretty, name it and take a copy into inventory BEFORE touching it. Where ever you want the position, just throw it on the ground and touch it. It will say the position that you can now copy and paste and then die. You will notice that there is an offset to adjust for your waist height.

But it also sounds like there is one other problem you are encountering. When you teleport, your avatar is moving very fast. Try putting llSleep(0.5) in the teleport script right above where it says llUnSit. This will stop any momentum you have before you stand.

vector offset = <0.0, 0.0, 0.5>;

default   
{ 
      touch_start(integer num) 
      { 
          llSay(0, (string)(llGetPos() + offset));
          llDie(); 
      } 
}