"Check volcanic activity" Goma Warnings Or Dangers Tip by Bonobo2005
Goma Warnings and Dangers: 4 reviews and 2 photos
Mt. Nyiragongo is still very active (03/2003) and it's probably dangerous to go up unless you go with experienced geologists.
When we followed the road to the base of Mount Nyiragongo we were stopped by some armed men who told us to pay $30 for National Parc fee which would include a guided and guarded climb to the crater rim.
However it didn't look very official and I could easily imagine that some further on another one would show up to demand something similar. I didn't pay (and didn't climb) so cannot tell you about that.
There's an alert system showing coloured flags (green,yellow,orange or red) everywhere in & around town.
But if it's red you'll probably have already wondered why some 100.000's people are running away. In that case it would possibly be very wise to stay away from Goma and watch the eruption from Rwanda.