Just a Firefox theme I whipped up. It was originally just for me, but I decided to share it with a few friends and they told me I should put it here on deviantART...and like usual I procrastinated.
I used Freewally's SMB3 theme as a base for my Sonic theme, so credit goes to him as well.
Sonic the Hedgehog and associated characters are copyright of SEGA
UPDATE: In case you're not familiar with Firefox themes, just drag the .JAR file that you download into the themes window of Firefox. It should automatically install from that point.