I use a digital recorder on my very long commute to capture ideas,
notes, random thoughts, to create to-do lists for when I arrive at
work and back home, etc.

I download audio to the software (Panasonic Voice Studio) but it just
stores and plays.  I want to manage files, categorize and have an easy
way to play them sequentially and delete tham in a way that I can take
notes fast.

Long ago, I used the foot pedal with a microcassette machine that worked well.  

Dan