How many songs does the IPod Nano 16GB hold?

Kind of as an estimate, I have all my music at 256Kbps on a 32GB iPhone, I have about 2800 songs on it. You should probably half that for a 16GB Nano if all music is at 256Kbps taking into account deggies post as well.

That depends on some variables including the format of the songs, quality level, length of the song, etc.