Often, I think of things.  I classify them as such (as "things") because the range and magnitude of these thoughts vary.  A lot.  Where I tend to spend most of my time is in the quagmire of the application of scientific discovery.  Sure, anyone can run around and tell the world about all the cool stuff we could do if a certain scientific breakthrough occurs.

Myself though… I tend to think of what’s going to get most negatively impacted by the discovery.  My latest thoughts have been dealing with parallel dimensions and/or time travel (depending on your viewpoints of the topics, the latter probably creates more of the former).  And what do I think will be most impacted by it?

The legal system.

Just think about it.  When science proves the existence of parallel dimensions, DNA evidence is no longer set in stone and lawyers can start dragging scientists into court to introduce reasonable doubt. 

"So, your evidence is tied to my client’s DNA, correct?  But what if it isn’t really his DNA?  There are any number of dimensions where my client exists in some variation.  How can we know without a reasonable doubt that the DNA is from my client in this dimension and not from some duplicate in another dimension who’d have exactly the same DNA as my client."

And then there’d be the imminent collapse of child support… and the Maury Povich Show. 

"And the results are in.  Bubba Jethro, you ARE the father."

"Now jes’ hang on there a sec, Maury.  I gots me a letter here from one of those scientist types that says the DNA in that there boy might not be mine.  It could be the seed of one of them evil dopplemegangers from another Die-mension."

"Bubba Jethro, you lying [bleepity bleep]!  You know damn well you’re my baby’s father.  Dopplemeganger, my ass.  I seen Star Trek and I know how ta spot one of those goateed evil [bleep bleepers] when I see ’em."