I do some GIS work occasionally.

I'm going to gripe about living in Britain and accessing publicly funded data.  Unlike the USA, where any data collected that is funded from taxpayers money and is then available to the taxpayer at no further cost, here in the UK data that WE pay for is not available to the people who paid the data to be collected.  I think this is a scandal and so does the Guardian so I'll refer you to their web site as they are far more erudite than I.

UPDATE:  As of april 1st (no joke) the OS have released some datasets for public use.  This Grauniad page has some details and there's also http://parlvid.mysociety.org:81/os/ where the data are available for direct download withouth going via the OS page where you have to fill in a request form then wait until they send you the download link.

I intend to make any data that I collect and any data that I find that is in the public domain available here as links to the source, or if my own data, some download links.

Disclaimer: I make no guarantee of the accuracy of any data on this page.  Do not use for navigation.  Obvious really.

Here's a start with some OpenStreetMap data sets.

http://downloads.cloudmade.com/europe/united_kingdom#breadcrumbs

http://www.mapcruzin.com/free-world-country-arcgis-maps-shapefiles.htm

After quick look at the strategi map set it looks to me like the OpenStreetMap data has more detail than the OS data set.  Specifically the roads appear to be of a finer detail, of course detail doesn't equate to accuracy and I haven't compared the two data sets as yet.  There's likely to be a quantative way to do this using postGis but I may never get round to doing it due to it being hard work and all.  Same goes for the river data at first glance.  How useful the data are going to be to the ordinary DIY GIS user is yet to be seen.

 An example of a government releasing data to the public is for Massachusetts, but alas it's in the US again.  We just don't seem to be able to grasp the point in the UK about publicly funded data as belonging the public.  Yes, I know that the OS's income is largly through selling the data, but that's a self evident circular argument.  The raw data collection is publicly funded and as such should be available to the people who paid for it.  What the OS do to it afterwards to add value and make it into a saleabale product is their business.

I forgot to mention, I use QGIS at home, as it's free and runs in Linux, Windows too I'm told.  If you're using the OS data you will/may have to convert the CRS EPSG ID to 27700 to display in degrees and overlay correctly with ther maps you may have.  Regarding qgis and OS data, I downloaded the streetview dataset for my region and tried to view in qgis.  All the tiles load in the same place, of course.  This is because QGIS needs a world file to calculate how to tile the, er, tiles.  I wrote a Python script to do this which simply copies the TFW files into the map data directory and renames them as *.wld files, no translations or reformatting needed.  The OS streeetview is exactly as described, it contains streets and buildings.  The lack of any topgraphical features and footpaths makes it of limited use to anyone planning off road hiking trips, although woodland areas and water features are marked. Actually some paths are, but in white on a white background!

I found http://www.fixmystreet.com where you can automajically report potholes and other street related faults to your local council.  Most useful site I've seen for a while.