One very important aspect of string theory is definitely testable. That was the prediction of supersymmetry, which emerged from string theory in the early '70s.
When you click on a link, you are replicating the string of code that it links to. Replication of code sequences isn't life, any more than replication of nucleotide sequences is, but we know that it sometimes leads to life.
My first phone was two tin cans tied together with string, and it worked pretty good.
I went through a string of A&R men who all thought I should be doing something different. One thought I should be a dance diva; another thought I should do Rock n' Roll; and one thought I shouldn't even be singing at all!