These are from the supplier of the issue straps, but with better hardware. Compared to the copy NATO straps they are much higher quality. I have bought several watches and straps from Timefactors - very quick and friendly service, VAT free to BFPO and owned by an ex-RHA type.
I like the Polo Shirt idea, too, and the G10 watch strap. I haven't worn my G10 watch for a while...
How about a lanyard, for security passes? Now, I know this seems a bit chav and we wouldn't all want to wander around shopping centres with phones and ipods hanging off us, but in my place of work we wear passes on these lanyards around our necks. Some staff have 'personal' lanyards and as I don't need to wear a tie (although I have worn my Arrse country number once and got stared at) I thought about the lanyard idea.
I am serious, but welcome all nature of responses.