Watch Your Sensor Ranges
I’m sure this is obvious to most, but be careful when creating sensors. I found myself sitting around in my theater today getting dialogs from the other side of the island warning me to not abuse a sandbox.
And yes, plural dialogs, so the other lesson is to make sure if you are going to sensor on a timer and address those you detect, you need to be sure to keep a cache of those you have already addressed in a list.
I’ll have to whip up a sample application some time that performs sandbox greetings. My approach would be to use the llGetParcelPrimOwners() function to get a list of everyone with a prim in the sandbox, then check them against a cache. If someone is not in the cache, send them the Sandbox welcome and add them to the cache.