Some interesting approaches to using data and maps. In times past Stuey I would have agreed with you that OS mapping would have been pricey when it comes to digital info. That is now a thing of the past. You can now subscribe freely to their OpenSpace API, very much along the lines of Google Maps. Depending on your level of computer competence you can add data to the mapping.
Of course the OS mapping does not reside with your computer it is served dynamically from their web server to you. But you can, once you have and API key, create a localhost if you do not wish to publish data. You can of course take screen shots. Being on a Mac I use Snap Pro X, which will also allow video sequences as well.
The downside to such mapping at present is the addition of very large amounts of information slows up the API. For example if the Aditnow database were added to a single OS map then you would be waiting for ever to see additional map data the was trying to be added. Here I've used a simple text file to add markers and data to an OS map.
http://www.kap.toadstone.com/kapmap/osmap.html The map is fully dynamic in the sense that it is scrollable and you can zoom in and out.
Another approach is to call gps data files using XML. This approach will allow you to put lines, shaded areas etc. But again really only for one instance or a few. Finally you can by using php call data from an online database, again vast amounts of data would slow the API down. The simplistic way round this of course is to either create multiple maps in order to separate/divide data up or as some have done to create layers as the OS OpenSpace is compatible with OpenLayers.
There are also a couple of ways to add data to the mapping either automatically or by using a database. The first is by ftp-ing a file to your server and then having that re-served using php. The marker then displays the latest information. Here I've used it for weather info from my weather station
http://www.biglow.co.uk/weather/php/osmap.php It's updated every 10 mins. But you could of course feed other info, like warnings, flood data etc. Click on marker.
You can also add data from a web page to a database and then for that data to be displayed on refresh. It uses TinyMCE to populate the database.
It all depends on how much you want and are able to get your hands dirty with code :confused:
Edit: for Mac OS mapping software Route Buddy is good & the OS OpenSpace can be found here
http://openspace.ordnancesurvey.co.uk/openspace/