The Occupy movement as it now stands, and considering its' goals, is a dead end for anarchists, just as Madlib wrote. I do see some value in maintaining some level of critical solidarity with the protesters in my town - while the vast majority are reform-minded, there are seemingly many who sense the poverty of the current state of affairs, and who have latched on to this as the movement of the moment, similar to the anti-globalization movement 10 - 12 years ago. I should be clear that my interest is not in converting these people, but in creating places where perspectives they had previously not encountered are present.
As to the original question being asked, an anarchist occupation might look like a lot of different things depending on the anarchists in question, but a few thoughts on how it might contrast with the current reformist occupations:
1. No accommodation to the police & state - Currently occupiers are going out of their way to play by the rules of and cooperate with law enforcement through either discouragement of and distancing from any acts of vandalism or direct confrontation, or through actual collaboration. Here in Seattle the organizers have maintained communications with the mayor's office, though I believe they might have moved to stop directly liaising with the police, they are operating within the confines of what the police are allowing them to do. When arrests happened, they were in a very formulaic nvcd format - everyone was on a list before hand (and everyone had the opportunity to get away), most people went limp, the crowd bore witness, blah blah blah.
Contrast this with what *might* be the actions of an anarchist occupation: no conversation with the mayor's office about permits, we are here, we are taking this park and it is ours. No accommodating the police - they are not welcome within the occupation and will be ejected if at all possible. A willingness to defend the occupation - Anarchists might identify strategic points to blockade and inhibit police access to to the occupation. Anarchists also might be less inclined to peacefully let themselves be taken by the state when it serves no real strategic purpose, or might act to prevent their comrades from being arrested.
2. No demands - The Occupy Seattle website has a list of demands which visitors can vote on so as to determine what is truly a priority (hey neat! democracy in action! see it here: http://occupyseattle.org/demands
). These demands are all based on the presumed maintenance of the state and range from calls, on the more radical side to "end" or "abolish" various aspects of the state-machine: "the prison-industrial complex" (56 votes) "the federal reserve" (41 votes), and "the drug enforcement agency" (60 votes) to the more milquetoast: "Corporate Accountability" (520 votes), a "fair and equitable tax system" (438 votes), and to "end privatization of the commons (natural resources, education, healthcare, etc.)" (145 votes). I could pick apart each of these things, but I will trust in the critical thinking skills of others in the context of this discussion - suffice to say, the demands being made that call for actual elimination of state apparatus are on the lower end of the priorities, while ones that rely on and further state control are proving far more popular.
Anarchists would not be making demands of those in power - except perhaps to walk away from that power (which is only done for rhetorical purposes anyway, of course they won't do that!) - instead we would be acting to bring about what we wanted, and to eliminate the things we oppose ourselves. Clearly, not everyone in the occupation would be interested in or support every initiative that was undertaken by other occupiers - but perhaps the occupation could serve as a point where individuals might meet and as a staging point for actions beyond the occupation.
3. General Assemblies and Direct Democracy - As far as decision making, communication, and so forth, anarchists here have used an assembly model which proved somewhat effective - it is not a decision making body or a place for "direct democracy" but a place to discuss initiatives and projects already being undertaken or conceived. Certainly in a long-term occupation of physical space there are some needs that might need addressing in other manners, and I mostly trust that this happens, though it is also important not to let some of the infrastructure work become too invisible, as this can create informal hierarchies and marginalize or sideline some people from taking part in things they might otherwise choose to do. I don't have a good solution for how to prevent this, and I don't think one model would fit all, though perhaps the affinity group/spokes-council model could or would be employed in some cases (I have mixed feelings about this model, but it is one possible choice).
Regarding the communication aspect - anarchists have found some pretty diverse ways to communicate their goals and objectives, and I expect these would be employed - from banners and leaflets to web presence (anarchists other than myself seem to be good at teh webz).
One point that I think must be brought up - all of this is being suggested in the context of a mental exercise - there are always more problems on the ground, not the least of which is that a semi-permanent uncompromisingly anarchist occupation will be met with fierce repression, and in all likelihood that repression will be viewed sympathetically by "the 99%" (which, after all includes the police, according to the current occupiers). I am unconvinced that attempting to emulate the current occupations but using "anarchist" methods is a currently desirable or feasible choice tactically speaking, in the United States.