Whether you're transcribing an entire interview, or just trying to note down a few lyrics, the endless clicking of Play/ Pause/ Rewind means it's usually a very tedious process.
PmTrans is an easy-to-use Java-based application which may be able to help.
There's no installation (although you'll need Java), pmTrans is a single JAR file which you can download and run right away.
Basic operations are very simple. Open an MP3 or WAV audio file, click Play, and start typing your notes in the text box provided. You can slow down playback speed or click Pause as required, and you can jump to any part of the audio file with a click.
If your typing still isn't fast enough to keep up, there are hotkeys to rewind by short or long periods of time (5 and 10 seconds by default, but you're able to use whatever you like).
PmTrans also offers a more automated "audio loop" option. Turn this on and the program plays 5 seconds, rewinds 2, and repeats. You're no longer manually rewinding by clicking buttons, or pressing hotkeys, and can concentrate on typing text.
Pressing the Ctrl+T hotkey inserts a timestamp into your transcription ("04:13", say, or wherever you might be in the file). This isn't just plain text, it's also a link: clicking it jumps to that point in your audio.
A "Find and Replace" dialog with regular expression support was a surprise, and pmTrans is also reasonably configurable (delays and hotkeys can all be customised).
It can't compete with the commercial transcription tools, but for a brand new, open source application pmTrans isn't bad at all. If you sometimes need to take notes from an audio file, then give it a try.