Mapping software

[#1]

Hi
Does anyone know of any cheap and cheerful mapping software please. Around 10 years ago I used MapInfo at work. Then an excel addin that got withdrawn in Office 2003 I think.
MS MapPoint has too many features so is a small fortune. I occasionally want to represent data by UK postcode area.ie turn a list of Data with postcodes into a map of the UK to show density by post code if you see what I mean.
There must be something that does the trick.
Thanks

[#2]

you can do some of it in Google maps, but I thing to get the density, you have to produce a circle that reflect the number of items at that point.
Google offer fre API's to do the plotting

[#3]

this picture is using An API, it show where I took some Photos

on the original, hovering over the icon brings  up the photo and details as per this also free web site http://www.weatherbonk.com/weather/summary.jsp?where=braintree&_id=&_className=weathermaps.weather.u...

[#4]

Thanks - I see what you mean.
What I really want to produce is something like this http://eyeofthefish.org/wp-content/uploads/2009/01/uk_postcode_map.gif
built from a database of data including the field postcode.

[#5]

how about this http://www.freemaptools.com/uk-postcode-map.htm