Ever since I got my current phone, all of my ringtones have been JPop or JRock songs. I just edit them using Audacity then transfer them over. Currently I've got the chorus to LU LU LU by GAM (i.e. the girls in my current avatar).
For voicemail/text message alerts I got a little creative. :anime: I took two file and put them together. The first has a Japanese girls saying "Oh ****" in English, and the second one has another Japanese girl saying "Mail is waiting" in Japanese. :laugh:
I also use my phone as my alarm in the morning, for that I use the chorus of the song "Matsuken Samba II". When you hear it over and over again it's just so annoying it forces you to get up to shut the damn thing off. :laugh: