Another alternative would be to do the transformation with sed or awk, or if you require more complex regexes, perl with the "-i" and "-e (single line of code)" options.
Cut has a mirror image program, "paste", but I've not yet hit a use case for it.
I used it once for counting n-grams while making a markov chain generator
This is great! I can't believe I've never run into "cut" before. In similar spots, my workflow would have been filtering the lines with grep and then opening the file in VI to finish the task.