Stan, I've had excellent service from the two Wilson cellular amplifiers I use, one in the car and one onboard. The iPhone specific amps I'm using are no longer made (no idea why), but I've talked with Wilson's tech support guys a couple of times and they get very high marks from me--they know their stuff! One key to great amplification is using a high gain antenna high on the mast. My antenna is a 3db gain white marine antenna mounted on a spreader on my mast at about 25 feet above the water. There are three types of amplifiers. Fom the Wilson website: Wireless boosters<http://www.wilsonelectronics.com/ProductListing.aspx?Category=6&title=Wireless>boosters require no physical connection between the boosters and your cell phone or data devices. Wireless boosters are powerful enough to support multiple cell phones and data devices simultaneously. Cradle Boosters <http://www.wilsonelectronics.com/ProductListing.aspx?Category=7> Built into each of Wilson’s all-in-one Cradle Boosters<http://www.wilsonelectronics.com/ProductListing.aspx?Category=7>is a signal booster, internal antenna, cell phone holder, and battery charger. It is ideal for hands free operation, and can be used with your Bluetooth device, handset or phone’s speaker. Direct Connect <http://www.wilsonelectronics.com/ProductListing.aspx?Category=8> Direct Connect<http://www.wilsonelectronics.com/ProductListing.aspx?Category=8>signal boosters require a physical connection to the phone and are designed for one user at a time. They powerfully amplify signal directly into your cell phone or cellular data card, allowing you to get maximum signal performance for rural or remote locations at a great value. More info at: http://www.wilsonelectronics.com/Mobile-Solutions.aspx I'd buy another Wilson in a heartbeat! No connection with the company other than as a very satisfied user. --Milt Baker, Nordhavn 47 Bluewater, Charleston Stan wrotre: Has anyone done any research on Cell phone amplifiers?? Obviously I'm looking for max reception gain and transmission power for GSM phones. Any good ideas??