I know this won't appeal to all cyclists, but I want to recommend something I beleive is a huge step forward in cycling safety.
I first saw this advertised on here and then made some enquiries and bought one - the wide Bike Eye mirror.
Fantastic and very simple invention that is brilliant on my commuter. Unbelievable rear view, you can see the cars 'sneaking' up on you, or the nutter that is coming at 90 mph. I have found I can pre-empt where I need to be in relation to what is coming at me from behind without constantly spinning my head round. In the city it's great to see where the next 'missile' is coming from. They relly are a great idea.
If they save a life, they have got my vote and as the advert states, you are able to see where your riding buddies are too.
Just thought I would pass on this pearl of wisdom.
Well done whoever invented it.