The website 'lygte-info.dk' has made a review of the 5V DC version of this module, which can be found here: http://lygte-info.dk/review/Power%20Mai ... %20UK.html
Don't go the route of buying a cheap iPhone wallcharger and modifying that, this module seems like a better and way more safe idea.
Be warned of the notes that the reviewer mentions though:
Read the whole discussion about this HLK-PM01 module @ http://forum.mysensors.org/topic/1607/s ... ansformers (advice on fuse & MOV is also mentioned there).Electronic wears down faster when warm, especially capacitors, i.e. keep it as cool as possible for long lifetime.
I would place a fuse or fusible resistor before the converter, the fuse is not supposed to be replaceable, when it blows it is time to replace the converter.
A MOV accross the mains input would probably also be a good idea.
P.S. Also see the other reviews at http://lygte-info.dk/ the guy has a lot of useful information on his website.