bansama: I've dabbled with a few. I speak English fluently (unsurprisingly) and normal* Japanese near fluently. I also used to know a fair bit of Latin and Mandarin, a tiny bit of Cantonese and Malay (as well as Malay-English) and smidgen of Italian (only learnt it as I went to Italy for a short holiday). Also learnt French in school, but could never get the hang of it.
* As opposed to the "technical" Japanese consisting of company specific terms that I deal with on a daily basis, a form of Japanese that even most Japanese have difficulty understanding.
Is it normal? I thought one of the problems they were having in Japan was that students were studying English but not getting fluent, even when they could write pass the relevant tests. I definitely could be wrong, but as an ESL teacher I'm always curious about that.
For me, I'm fluent in English and am somewhere around Intermediate with German, I have excellent listening skills, but my vocabulary is pretty embarrassing at present. I can however construct all sorts of sentences and usually get the correct endings on things.
In the very near term I'm going to be studying Mandarin Chinese on a daily basis.