Publicity helps!
When I first arrived I contacted the Swedish Equestrian Federation and asked them for introductions to local riders and riding schools that might be interested in being part of my research.
I contacted her and, of course, she was busy herself and so we didn't actually get to meet each other until several prompts later and by then it was almost the end of June and three months later. Mari is a well respected coach here in Sweden, as well as being a researcher and she has taught many of the local riding school coaches and so knows a large number of people.
Mari maintains a web site where she publishes news about advances in equestrian training. She put a brief reference to my work (in Swedish only) up on her web site and this was picked up by a local reporter for the Swedish Equestrian magazine Hippson. Hege Hellström (the reporter) and her partner came to the Wireless@KTH lab where I work and interviewed me. Subsequently she published this article in the magazine and on their web site (at www.hippson.se/cldoc/39634.htm). If you want some idea in English of what these Swedish pages say then try Google Translate at www.google.com/language_tools?hl=en .
Interestingly, Hege's partner also works at KTH as a researcher in the same building as I work! As well as giving my project this publicity she and her partner have both volunteered to participate in my research and have organised for several others to participate as well.
By volunteering, they have both lifted my meagre numbers of volunteers but this changed the day the article was published! Since then I have been inundated with offers by local riders to participate and so in the space of less than a week I have gone from having only a small number of volunteers after months of work to having almost a full complement of volunteers, publicity really does work.