This plugin shows fireworks on your WordPress blog. I think it's pretty stable by now, although the images still aren't that nice. If you're a designer and you like this plugin, feel free to submit nicer explosions or rockets. You should be able to see the fireworks on this page.
The plugin is similar to my snow plugin and shares some code.
You can download it from the WordPress plugin page.
WordPress plugin demos are disabled as I don't use WordPress on this site any more.