I'll be in Panama City in a couple weeks, so in traveling to any new destination you read about which areas of the city are bad, of course.
Here's the potential "trouble" areas I've read about
:
La Exposicion
Calidonia (one travel guide I was browsing, said from about Calle 35 south, it starts getting more dodgy)
Casco Viejo (at night)
Chorillo
Curundu
This website has some 'good' pics of the bad areas:
http://www.travel-images.com/panama-city9.html
Of course, bad things can happen anywhere, so I'll be aware as normal even when out & about in the better areas of town..