Hi Julian,
I have built the 50 mW Veronica fm transmitter and it's very good. I built my own power supply and at first I had trouble with mains hum until I regulated it.
I can also recommend the 'Wireless Man' from the following :
http://www.lektropacks.co.uk/dept.as...74&dept_id=102
If you buy just the Tx and the power supply it works out cheaper than the Veronica, and it's ready to go. I use one here in France to rebroadcast Radio 4 (and anything else from my digibox) around the house. My neighbours are outside of the signal strength. I haven't checked for harmonic radiation which I guess is rather important.
Another mystery re licence regulations is that my daughters baby alarm, which broadcasts on the fm band (in the UK), can be heard at her neighbours house four doors away. This was bought in Boots!
Gordon.