The guys at Mozilla have developed a Joga extension which will allow you to follow your team and keep up to date with the latest scores in Firefox.

Joga is a football community built by Google and Nike. 

According to Christopher Beard, the extension allows you to:

• customize their browser with one of 32 national team themes
• track the latest scores and headlines
• view awesome football videos
• connect with communities of football fans
• and, receive up-to-the-minute match and goal notifications while browsing the Web

FootieFox

FootieFox is a free extension which also displays football scores. The difference is FootieFox scores are updated by users. Screenshots at the FootieFox website.