In case your not familiar with representations.
There is new since 9.2 a cartographic representation available.
It allows for rules based on data fields to determine symbology.
Admittedly it is very useful and powerful for single entity manipulation to show it how and where you want.
One problem with it is that there is only one way to get a representation from existing symbology.
Using "convert symbology to representation" it creates a new feature class (db only) and creates all the rules and symbology for the representation. These symbols are not the normal esri symbols so there are some issues and restrictions for maintining that.
However at that point you have a (personal, file or sde) gdb with symbology in it.
Whenever you add that data to a new map the symbology is already there and if you have more than one rep you simply click between the reps you have defined.
As I said very powerful.
The REALLY big drawback I just found is that when you edit the original value that created the rule the rule is not updated.
An easy enough fix if you are symbolizing with only one field.
As luck would have we are not.
Now the question.
Has anyone used a script to update the rule_id field from more than one originating value?