I've installed the plugin on Joomla 1.5.14. On the front end, where users and guests would see, it does randomly have snowflakes falling. However, it also creates the same effect on the back end. That is, you have snowflakes falling in the adiministration area (back-end). There's a few issues:

1.) Create the option to allow admin to set whether the snowflakes would appear on front-end, back-end, or both.

2.) Fix problem with snowflakes on back-end. On the front-end you see snowflakes. On the back-end you see red X's falling. It seems that when it does this on the back-end the plugin is unable to locate the snowflake images. Therefore, you get a red X in a silhouetted box.

Cute little plugin, its works straight away and you can set the quantity of flakes

I hope this review is added here, because last time it wasn't...
This plugin doesn't work. After enabling the plugin my site didn't work anymore. I got a blank page with a fatal error (something about a "call to member and a non-object" on line 31).
I had to delete the files manually on the server to restore my site.

cute plugin.... nice decoration for your page for xmas... snowballs falling in your page....good one !