Radio Communications Gripe

And speaking of communications, here's a gripe. A frequent occurrence typically involves VFR flight following. The idea behind flight following is to have an extra pair of eyes looking out for your flight, even if you're in airspace that does not require you to talk to ATC. We radar identify your aircraft and provide you with traffic information, as well as significant weather developments along your route of flight, workload and equipment permitting. What's my beef? Pilots who call up asking for flight following, and then leave my frequency without telling me. I can't possibly provide you with information if you're not listening to me. Also, if you leave radar coverage, how will you know if you can't hear me tell you? You may assume you're being provided with a service when I may not have seen you on radar for a long time. ATC understands the need to make radio calls to MF/ATF areas, FSS and others. All I ask is to extend the controller the courtesy of telling me when you plan to leave his frequency, and let him know when you're back with him.