I've taken my first crack at a Firefox extension for SnipSnipe out at the Mozilla extensions developers sandbox. Take a look, it's easy to use! (Although I'd appreciate anyone with FF sandbox access to download via that channel, you can also download the plugin directly from here)
After installing the plugin and creating a user account on snipsnipe, find some code you like and highlight it. Right-click and select "Share Snippet..."
This will open up a new tab pre-populated with the snippet and the URL where it was found.
Just give the snippet a title, short description and some tags (don't forget the programming language... that's how snipsnipe knows how to highlight the code).
Submit the new snippet and that's it! Add all the snippets you want... it's free :)