Plax said:You can get a Garmin Nuvi 250 sat nav for under £100 e.g;
http://www.amazon.co.uk/Garmin-Satellite-Navigation-System-Mapping/dp/B000OV16MQ
It has the option of using it for bicycle or pedestrian and they also do a bicycle mount for it;
http://www.amazon.co.uk/Garmin-Hand...?ie=UTF8&s=electronics&qid=1248114497&sr=1-14
Of course it won't record any of your cycling information such but if you can get hold of a cheap Aldi computer that does HR as well as odo, mph etc you can use it in conjunction with that.
Could be useful on an Audax. You will need to sus all the controls and INFOs before you go.
Second thoughts, if there is a cycle path or footbridge that cuts a mile off the road distance, this Nuvi won't tell you about it.
Third thoughts, using an Autorouting SATNAV to get from one control to another MIGHT take you a different route than the organiser has on the routesheet.
I always build a route for my Edge which follows the routesheet. When I get the Brevet card at the start, I check for the dreaded box entitled "SECRET CONTROL" If there isn't a 'secret', its a free route between controls and the auto routing on Topo GB guides me.
So no, not a good piece of kit for Audax. OK if you're a delivery boy.