I've been translating since about 2004, though almost always as an amateur. I used to translate into Italian, since that's my mothertongue, but in the last few years (especially since November 2007 when I first posted my work on MangaHelpers) I started working with English too. I'm definitely not perfect, especially because I'm not a native speaker, so if you spot mistakes in my translations please PM me about it, I'll gladly correct them! :D (obviously, same goes if you think my translation is wrong regardless of the English)
As a reference, I passed both 1st and 2nd level of the Japanese Language Proficiency Test, 2nd in 2004 and 1st in 2006. I've been in Japan 5 times (for about 1-3 months each) and I've happened to work as an interpreter, though I still have to improve at that.. I would like to make it my future job, actually, but for the time being I'll consider it an ambition/dream.
Also, I'm currently a nikkensei (Japanese language/culture studies) at Tsukuba University after winning a Monbusho scholarship. I'll be living here for one year, during which I hope to further improve my skills and maybe even find a job :)