I have a bit of an update for the prepaid SIM question. I went to LIM on Thursday and could not find my prepaid SIM to take with me.

I asked at the Claro shop at LIM and they said they would sell me a prepaid SIM for S/.75 but I would have to find a way to register it and they would not do it for me.

I subsequently went to Ripley in Miraflores where there is a Claro stand at the top the escalator. They sold me a chip for S/.15 and offered to register it to my passport (which is bending the rules somewhat) I didn't have my passport with me, so they registered my Colombian cédula as a Peruvian DNI. Ten minutes later I had my chip working and it came with 15 mins of Claro to Claro calls on it.

Top your Claro chip up (which you can also do at the wee stand in Ripley) then send a text message to "779" with the text "1d1" this will give you 24 hours of mobile broadband for S/.1