For Hong Kong residents who find loud mobile phone conversations on the MTR or in movie theatres annoying, the prospect of respite must have been sweet, however short-lived. At last week's Electronics Fair 99, local inventor Anil Vora was said to be displaying his latest gadget - a 'mobile squelcher' which can be aimed at a person engaging in an offending conversation. By interrupting the phone signals, the squelcher is supposed to cause the conversation to break up and the talker to give up on the call. The squelcher is brought to us by the man who invented the hurricane-proof umbrella (it has holes but Mr Vora guarantees the user never gets wet), the no-burp milk bottle (which lets air out as baby is feeding) and the toothbrush with built-in dental floss. Mr Vora's previous inventions may have defied the laws of physics and common sense, but his squelcher has met with a more down-to-earth opponent: Hong Kong's Office of the Telecommunications Authority (Ofta). It seems that no radio device of any sort can be used in Hong Kong without a licence. Use, possession or sale of any unlicensed radio device was subject to a maximum penalty of $50,000 and two years jail, an Ofta spokesman said. Ofta also had no intention of licensing jamming devices because the technology was too indiscriminate and could block emergency calls. Calls to Mr Vora's company, Global Inventions, failed to produce him. But a woman claiming to be a member of his household staff interrupted her vegetable chopping to say that Mr Vora had decided, upon the advice of solicitors, not to manufacture the squelcher.