List & Record Tools 1.0
This scripting addition from Late Night Software lets you manipulate AppleScript records like real dictionaries and do set operations on lists.
get user property "myage" in {myAge:42} --> 42
intersection of {1, 2, 3} and {2, 3, 4}
 --   Result:
 --   {
 --      2, 
 --      3
 --   }