Acknowledgments

My thanks to all those involved in this collaborative project at IAC, NRAL and MRAO, which has been funded by PPARC, DGICYT and EU Science Plan. Special thanks to the rest of those people who comprise the Tenerife Group; Rod Davies, Rafa Rebolo, Anthony Lasenby, Carlos Gutiérrez, Stephen Hancock, Roger Hoyland and Bruno Femenia.