Nato/G8 Summit - Chicago - May

First off, still getting used to the new forum and sorry if this is in the wrong sub-section.

I have been contemplating going to the protests in Chicago this coming may. While the call has been put out to flood the city beginning on may day, I just cannot possibly make it there for a full month. So I have been thinking about heading down for the 19-21 or whatever the three days were which was the peak of the meetings. While I have heard that this could be the largest anti-globalization protest in NA sine Seattle I have also heard that the police crackdown will be insane and that many of the Chicago based activists will be staying home. Anyone here also going, or hear of what is to be expected?

I also must point out that this will be my first protest of any significant size and am pretty nervous about losing my protest virginity at such a large scale event under a police state. I also should mention that I am from Canada and will have to cross the border, which may complicate things even more. While I am over 18, I am under 21 and not sure if that will affect anything in the states.

I guess I am asking for any advice seasoned protesters can give me be it about crossing the border, what to expect in Chicago, what I need to be prepared with in case of arrest. Also I am most likely going to be driving down and need to roadtrip on the smallest amount of budget possible which will probably mean most of my money will be going to go towards gas. Are there places to stay for free or cheap down there that are not likely to be raided?

Thanks in advance for any help which can be offered.