Restart button to restart particle system (or space bar, or right mouse)
Save button writes settings to Lua file in app save directory (or s)
EDIT: I got sick of re-entering values. Now supports multiple save files, where filename=timestamp.
Save button overwrites the current file. If no save file exists on startup, it will create one using default settings and set it to current.
Copy button copies the current file and sets it as the current file.
Revert button reloads current file, discarding any changes.
Delete button nukes the current file (unless it's your last one).
There's a widget for scrolling through available files.
[/color]Note: It will NOT warn you about lost changes if you click Delete or use the selection widget to switch files. I'm too lazy to make a confirmation dialog.
It has some included images. To use your own, drop them in the directory and edit particles.lua.
After playing with it for a bit, I realized you could do some crazy sh** with animated parameters. Someday.