I had the same issue with my baby, Boss. We have a trainer that comes to our house. She has taught us to stand straight up, very still, do not move your feet at all (we had to keep shoes on in the house for about a week, it's very hard to keep still with those sharpies digging in!) chin up, and make a growl noise, do not look at him, your should have very stern stance.... Say the word bah, but like a growl in your throat. As soon as he stops, you praise him with a good boy. It took about a week of constantly doing this, but it was worth it. He doesn't bite at our feet anymore! Good luck!
[MENTION=9501]mommaofbrutus[/MENTION] - submitting your dog or pinning him as you've said will work but making sure it's done in the correct way makes all the difference in the world ... when a dog truly submits he/she will remain in the submitted position without being held or touched in any way and will only get up when told it's ok, your energy plays a big role in this! if you are calm & assertive when submitting, your dog realizes this is a correction and not anger, if you are angry when you try to submit your dog it will have that fight or flight response ... so when Brutus starts to get worked up give a sharp "ATAT" type sound (distraction is a great training tool) you can snap him out of it before he gets to the out of control moment ... my 3 now have learned to stop what ever it is they are doing by simply using sound aversion, if I say ATAT or clap my hands their little butts hit the floor and wait for more instruction. I am a firm believer in Cesar Milan's Calm Assertive Energy when training my troops and I also use positive reinforcement, for the most part my 3 are very well balanced but like anyone who has a bulldog they have their moments but with the right attitude from me and 100% consistency in their rules, boundaries and limitations we can get back on track very easy after a misstep
I 100% believe using Calm Assertive Energy, setting firm Rules, Boundaries & Limitations and always being Consistent our dogs are more comfortable and confident