I'm trying to use a system that parses the data as a Lua program, as detailed in the Programming For Lua book. So you're storing presets exactly like they're kept in the script, plus they're human readable and editable.
I'm getting the pieces together one scrap at a time, at least in the last week or two, so it has been slow.
I hope to keep a preset file that contains the user presets and the last used settings. If it works great, I figure it'll be usable for everyones scripts.
After that, I want to put in sliders :P. Others have done that neat stuff, so I'll copy that from there.