Objects have a persistent ID assigned upon build from Terrain Builder. I'm also assuming they are stored in a map in memory for internal access.
These ID's are simply obtainable by doing object.GetID(); and you can set them with object.SetID();

It would be nice to have a way of obtaining each individual object via their persistent ID, without having to iterate over ever map object on world start.

Sample Code:

GetGame().GetObjectById(299596);