export - Photoshop How to save selection to PNG

I have a largish PSD file with a couple of hundred layers, that I would like to extract selected areas from into PNG files.

Areas can consist of a couple of layers.

Being new to Photoshop, I have been using the following workaround. Duplicate needed layers into a new scratch PSD file of same size, TRIM to transparency, Save As PNG, undo TRIM, hide layers, rinse and repeat...

I suppose I could do it without the scratch file and just crop selection, Save As PNG and undo, but there must be a nicer method.

What other ways are there to accomplish this export of a selected area to PNG?

EDIT: This is on Windows Xp running Photoshop CS3 Extended

Answer

• Make your selection


• Edit -> Copy Merged


• File -> New (Photoshop should automatically suggest a new canvas size to match the selection size)


• Edit -> Paste


• File -> Save As (PNG)


• Rinse and repeat... (keyboard shortcuts are handy here)

(Tested on Photoshop CS4)