You should set up a simple cron job to backup your history file (to somewhere else in your home directory) on some schedule (hourly?) and then when this happens just have an short alias that restores the last backup.
It's really handy to have stuff in history. But there's a ton of crap I don't need.
What I need to do is get better about scripting the stuff that I'm invoking frequently. Though zsh probably has an extension that does this for you, and scratches your back.
Mind: virtually all my shell scripts start off as one-liners that I've invoked and re-edited (M-x M-e FTFW) until I've realized I have something worth saving.
