Grabbing auto_increment during insert?

Apologies for what's probably an extremely newbie question.. Is there any way to have a database return its auto_increment field during insert? I have two different tables, when one inserts, I'd like to be able to assign the value of the new auto_increment field to another field in another table. I guess I COULD go and make the second table auto_increment along with it, but that would require a complete rewrite, and I'd like to avoid that... Anyone have ideas, suggestions, or preferably.. an answer to my question? :) Thanks -Jason