Omega Seamaster Planet Ocean (PO) (Std. size (42mm), not 'Big' PO (45.5mm) on a 20mm 'Tudor Heritage Chrono' "style" NATO. (Click on photo for high-res. image.) Photo found here: http://forums.watchuseek.com/f20/just-got-my-new-omega-po-xl-need-help-finding-cool-nato-strap-summer-683309.html This NATO is made by deBeer Paris http://www.debeerwatchbands.com/nato-nylon-watchbands.html
The re-envisioned Omega Seamaster 300 Master Co-Axial, modeled closely upon the famous Seamaster of the 60s, caused quite a stir in the horological community a few years ago. It is a bit thick for my liking, but boy, is it a handsome sight with a leather nato strap.