Regular monitoring of the light curves of blazars has become increasingly valuable as space missions such as ROSAT, CGRO and ASCA have subjected many objects to detailed multi-wavelength monitoring. Over recent years collaborations such as the OJ-94 collaboration have benefitted greatly from the input of amateur astronomers observing both visually and with CCD. More recently amateur observers have given valuable service advising of objects which have entered outburst and which are targets for Target of Opportunity Observations with satellite observatories. We encourage amateur observers to take part in such monitoring campaigns and to communicate their results in the appropriate manner when they detect unusual light curve behaviour.