I use the [Info] button to select the viewfinder-zoom feature (aka MF Assist or Focus Assist), so that manual focus will be assisted by a magnified image (7x or 10x). (I Press OK to actually zoom in)
When done focusing use the "OK" button again to cancel the zoom, since pressing the shutter does not do so. (The G1 does cancel zoom when you shoot!)
A half-press on the shutter button should cancel the zoom, as it does on the G1. That would make things nice and fast.
Is that feature also available on the E-Pen series? Did I miss something in the manual?