Nuclear bombs are neither good nor bad, they're just a tool. Since they're so powerful you should carefully consider the consequences before you use them, but that applies to any powerful tool.
Nuclear weapons have a few niche civilian uses. Sealing an underwater oil leak is one such use that is particularly relevant today.
See: http://www.reuters.com/article/idUSTRE6611RF20100702
Also: http://www.wired.com/wiredscience/2009/04/yourfriendatom/
What could possibly go wrong?
http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsi...
They're a tool. The "mass murder" thing is a human decision.
The wikipedia article for peaceful nuclear explosions didn't show many other successful uses. Are there others I may not be aware of?