Quite a lot of recording of tracks in the streets of North London / Barnet. This is done on a Garmin etrex and a bicycle, in my spare time. I've taken to popping out on my bicycle at lunchtime, and attempting to cycle along any street that hasn't yet made Openstreetmap. The whole of the N3 postal area (Finchley, North London) has been mapped (comparing a list of street names from the council with a list of street names in a bounding box in Openstreetmap), and I think I was first to claim such a feat - though it's since been repeated in Cambridge.
I've written route planning software in the distant past, and would like to get an open source route planner code working with the openstreetmap data.
I'm also considering writing an on-the-road editor / route planner thing that will in real-time work out what segment you're driving along, which is a good start, and any key/values. This is indended for use by a passenger in a vehicle, so that unlabelled streets can be easily labelled, and new junctions notes. It could also automatically note going into uncharted territory, and start laying down segments, providing the GPS signal is good enough.
I've recently been tidying up some of the motorways in the UK, making sure that they are labelled, have ways defined, and that the segments are aligned to point in the correct direction, and that the junctions seem to make sense. I've written a few perl scripts to help in this in conjunction with JOSM.