-things to throw. one great thing to bring is rotten vegetables to throw. makes nice and messy windshields for the visiting republicans, and won't ruin their car, so they can't have you arrested (since there is no damage). and pretty much anything in a paper bag is good to throw. if you don't want to hurt anyone, just fill it with flour or dirt, or a water balloon filled with vegi oil (its hard to swing an oil coated baton on a hot day.). any thrown object will cause someone charging at you to pause, giving you a precious few seconds lead.
-also, a nice stiff piece of wood, preferably bamboo to use as a sign holder/flag/self defense. i'm not suggesting attacking the pigs with it, however, a seven foot long staff will keep anyone from getting closer than seven feet to you.
- a change of outfit. VERY IMPORTANT. under your hoodie/mask/protest gear, dress like a yuppie. they will have cameras, they will be recording you, and they will be taking your description. so if something fun happens and you are involved, the moment you get out, ditch the hoody, etc, and presto chango, you're just some U of P college student or SJ resident out for a stroll. if the cops can't place you at the crime, thats good for you in court.
- of course, safety gear like thick clothing, helmets, masks, etc. and water bottles for refreshment and pepper treatment.
-MIRRORS. these are very nice at blinding cameras being pointed at you, and spying cops, and rooftop snipers, etc etc. and they can't construe using a mirror as an assault or illegal.
so this is just a small list off the top of my head, i'm sure there is more, be creative. oh and just one more word of advice. don't charge the pigs or try to fight a pitched battle with them. they are better armed. if they charge, run away and outflank them. you can always move quicker than they can. hit and run is the key.
have fun. hehehehehe.