I have one - purely for practical reasons you understand

actually that is true. I do a lot of hiking and cycling.
(well ok - I admit it - it also slightly appeals to my perverse nature to occasionally try to imagine what it might have felt like if I had been going the opposite way, although in my case it is just a way of thumbing my nose at my ongoing need to be female rather than any serious desire to return to my original state.

Sorry that really isn't meant to offend anyone.)
I'm not sure how well it would fit the bill if you wanted something which could pass more than a casual inspection though. But it works just fine and it isn't that expensive. I have one in the pretty pink carry case... you guys might want something a bit less girly!
You can buy them direct from the manufacturer here
http://www.whizproducts.co.uk/en/product_shop.aspx Delivery takes only a few days within the UK.
EDIT
Darn it TAY beat me too it.

Anyway for what it's worth it gets a recomendation from me.