In recent years, launching and tracking High Altitude Balloons has become a relatively popular hobby activity.
Sending a package of instruments into "near space", by balloon, can be a cost effective way to test equipment and techniques that can then be applied to other space-related projects. Below is a link to a schematic showing one HAB project currently being pursued in Manchester.
https://dl.dropboxusercontent.com/u/22560302/msp-balloon.pdfAn excellent source of information is the wiki of the UK High Altitude Society
http://ukhas.org.uk/