I do like a bit of firmware rummaging. Not on my own part, of course - I'm a bit too OCD to get my hands dirty - but I enjoy reading about the tidbits and curios others turn up while delving through a gadget's guts. Latest news on the iPhone's unlocked capabilities is sign of five new programmes or widgets, discovered by the iPhoneology crew.
(the icons above are from Mac OS X Tiger, and are potentially what the iPhone icons may look like)
The programmes - Mobile Radio and Unit Converter - and widgets - Phone Book, Translation and World Clock - look as though they could be unlocked with, you guessed it, a simple firmware upgrade. Since, however, there's little sign of an FM hardware receiver inside the cellphone, some are suggesting that Apple might be planning a streaming radio service instead.
[via ModMyiPhone]
A radio stream, would seem appropriate for the catchup improvements Steve said dot mac would be receiving in the near future.
Or, and this is a big capital OR! It could be something blue tooth releated. Perhaps a 2way radio within a limited short range area.