Core-Data Multithreading question about save

FROM : Dex Morgan
DATE : Wed May 21 22:25:18 2008

Hello guys
What's the way to make visible newly inserted message (in threaded 
managedobject context) into the main context? I've used -save:  and it 
works but a save for each insert generate an overhead (note: I need to 
'see' both previous newly inserted object and old objects).
Any hint?
Thanks