How can I make Find My Friends display distance in miles rather than km? I'm in the UK, where (like the US) we use miles to measure distance, not kilometres. However, on both my iPhone and iPad the Find My Friends app in iOS 5 shows distances in km.

If I go to Settings > General > International and change my Region Format setting to United States, Find My Friends automatically switches to displaying distance in miles. Switch back to United Kingdom and frustratingly I'm back to km. Is there any other way to make Find My Friends pick up the correct unit for UK users?
No. The app doesn't currently have an override and simply takes the distance units from the system settings. 

It surely would be nice to have finer control, but the code isn't there to make a change today.