Learning to use Firefox's keyboard shortcuts can reduce how often you reach for the mouse while browsing, especially for some actions that the mouse just can't accomplish.
When writing this post at Lifehacker, I had neglected charging my wireless mouse for quite a while and found that I didn't really need it at all.
Now, you might be thinking: "What? Just because you forgot to put your mouse on the charger, I have to learn all about operating Firefox without a mouse?" But there's more to it than that. Many people find the experience of not having to move their arm to click on every link much more pleasant. Check out the list of FF shortcuts below (some you might know, others you might not), and before long, you'll forget about that little rodent next to your keyboard.