i am not exactly clear about the legalities, and i don't know if LLC is the best way to go; however, forming an LLC is essentially a start to founding an organization that will be doing things that A) may or may not involve money and B) may or may not involve liability. the key is "maybe." i also don't think we're talking about starting just a housing co-op like quimba or others, but rather something more complex (see link below about social co-ops).

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as far as i know, if we ever need/want to open a shared bank account without individual liability, we would need to start an LLC. perhaps there is another route? good question for nasco.

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LLC means Limited Liability Company, and a cooperative can be a type of LLC, according to wikipedia:

http://en.wikipedia.org/wiki/Limited_liability_company

see also info on housing coops:

http://en.wikipedia.org/wiki/Cooperative#Housing_cooperative

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it also seems like we're not just wanting to start a housing co-op, but rather something along the lines of a Social Cooperative:

http://en.wikipedia.org/wiki/Social_cooperative

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and fyi:
a cooperative has been defined in the International Co-operative Alliance (ICA) Statement on the Co-operative Identity as "an autonomous association of persons united voluntarily to meet their common economic, social, and cultural needs and aspirations through a jointly-owned and democratically-controlled enterprise."
+ see http://www.ica.coop/coop/principles.html for more delicious information.

if we're gonna go, let's go all the way. as sylvester stalone says, "over the top!"