Possibly switch to XML-format configuration file.
Should probably clean up ~/.randomplay_history eventually--the file currently grows indefinitely.
Maybe check for free disk space before writing history file, although an increase of 10-15 bytes disk usage per song played is pretty minimal.
Possibly build an index of available files so the whole directory tree doesn't need to be traversed every time randomplay is executed; this can take a long time with a large directory tree or over NFS.  Advantage of the current system is new songs become immediately available and there is no structural overhead.  Maybe have --(re)build-index and --use-index options or something like that.
Random album feature