sorry to disappoint you Khaos but I have forcibly evicted squaters before :) the things we do for money lol , there are some great squats around though if you don't mind train tunnels or stormwater drains :) ps Khaos I think this is your best profile image to date .
About three years ago I took off for a week. I lived (mostly) in a bad ass house with an open elevator shaft while it was under construction. Besides the obvious lay-low and don't be seen there is very little to it. I suggest going to sleep early and being up around 2 or 3, especially if it is in an area with a lot of bums (try to avoid areas with a bunch of bums if possible because they are usually pretty crazy). It is a good idea to sleep on top of whatever you have (or to shove it down your pants). That's about all a week taught me.