I'll be spending some time in the Villette / 19th arrondissement area of Paris. What sort of a neighborhood is it? (Safe? quiet? entertainment district? etc)
http://www.ourparisforum.com/index.cgi?board=reports&action=display&thread=2170
Have a look at this, posted by a regular paris visitor, who's is a forum friend on the Our Paris Forum.
HTH somewhat, never venture out that far myself, but this lady was brave enough to do it.