option 1 : bring the console to your home? set internet, and do the hack yourself. You are more used to console hack anyway.
option 2 : modmii. Prepare everything on your computer, it will download the needed files from internet, you put all the files on SD and you go to your friend's home. follow the generated guide from modmii, it's all offline.
option 3 : d2x has an offline mode, but you needs files downloaded from modmii .... better just follow modmii instead. don't look for option 3.
greywolf : thanks, I always forget that post's url.
I put it in my
wiki page list of useful url so I don't forget about it anymore
until I write all proper guides in the "full guide", to put all my guides to the same place.