An article proximity indicator including at least one antenna having at least first and second ranges of impedance, the second range of impedance being at least partially different from the first range of impedance, the at least one antenna having a first impedance within the first range of impedance when in proximity to an article having a given dielectric constant and having a second impedance within the second range of impedance and not within the first range of impedance when not in proximity to the article having the given dielectric constant, and a proximity indication generator operable, in response to receiving an indication that the impedance of the at least one antenna has changed from being within the first range of impedance to being within the second range of impedance, for generating an indication indicating that the at least one antenna is not in proximity to the article.