Your comments

I was unaware of that, but it does seem to do what I want!  It's a little fickle, as sometimes it won't go to a function, even though it's in the ctags file. Also, for Fortran, which is not case-sensitive, it won't find some functions because of inconsistent capitalization between a function call and a function definition (maybe there is an option somewhere that will fix this. I'm usually really careful to be consistent about capitalization, even though Fortran doesn't require it, but this certainly exposed some places where I wasn't).

Still, it may just be my inexperience that's making me overlook the obvious fixes for these problems, and I'll definitely start using it.  Thanks for pointing this out!
The ability to right click on a function name in a function call (for example), and go to that function wherever it's defined (perhaps in a different file) in the project would be extremely productive for me.