From MayoClinic.com --
Cellulitis (sel-u-LI-tis) is a common, potentially serious bacterial skin infection. Cellulitis appears as a swollen, red area of skin that feels hot and tender, and it may spread rapidly.
Skin on lower legs is most commonly affected, though cellulitis can occur anywhere on your body or face. Cellulitis may affect only your skin's surface, or cellulitis may also affect tissues underlying your skin and can spread to your lymph nodes and bloodstream.
Left untreated, the spreading infection may rapidly turn life-threatening. That's why it's important to seek immediate medical attention if cellulitis symptoms occur.
Needless to say, I didn't wait three days. I went to the doctor the next day and he prescribed an antibiotic. I've been on them for five days now and my leg is looking a little better. The swelling has went down and it's not as red. Hopefully it will clear up soon.
I told my wife that if I lose my leg, I want to have it stuffed so that I can still admire my tattoo. Then I'll get a peg-leg and become a pirate. She doesn't think that's funny. :)