I mentioned Bloom in a recent post - a kind of DIY ambient music-making app which uses the touch features of the iPhone and iPod Touch. Now RJDJ goes even further - turning the sounds and movements in your immediate environment into a soundtrack for your daily life. It only works with the iPhone unfortunately (which has a built-in mike, unlike the iPod Touch). So I haven't tried it out myself (unlike Bloom).
But do check it out for yourself (it's a long video, but gets really interesting after 3-4 minutes) - I think the emerging 'app economy' is going to be awesome, with big opportunities for Irish developers: