A great source for both fans and owners of these devices have been found on newsgroups. From development to the technology in which they're based, many newsgroups are hosts to dedicated discussions of the different phones and platforms they're based upon.
As an example, newsgroups such as misc.phone.mobile.iphone hosts general discussions of fans of the iPhone. Users of the recently released Google phone, the G1, have been active on alt.cellular.t-mobile - the only US Carrier suporting the phone. While patiently awaiting fans of the new Palm Pre have been getting leaked details of the new phone on alt.comp.os.palm. Other newsgroups dedicated to the development of the platforms and the phones themselves have been an invaluable resource for developers. The newsgroups have been responsible for creating and maintaining some of the core functions these phones feature.
General chatter on providers, service and technology also are prominent on Usenet. For the US, alt.cellular.attwsand alt.att have been a meeting ground regarding ATT service, while the UK community meets upon groups such as uk.telecom.mobile and tw.bbs.rec.mobilecomm.
Many other newsgroups exist on the subject as well that cater to different phones and providers alonside the other thousands of newsgroups that exist on Usenet today. Many of these newsgroups came into existence even before there products were released, as others will be created as technology and advancements are made.