What are you exporting from?This is typical of uni-heads. "they don't care about resolution".No, but you'll all care when your poster comes out looking like spaghetti.If you send me a working file, I can run it through distiller and make sure it's at a decent res with minimal file size.
Distiller will just compress the huge image.Which is fine if the poster requires the whole space as an image but it might only require small image areas in which case you could get a full quality file at 6mb maybe.It all depends on the design of the poster really.