It's summer time, time to close off that street and have a block party with the neighbors. Here's how to do it:
In the city of Ann Arbor, you need a variety of permits and permissions to block off a street for a party. First off, there's a helpful (and required!) PDF from the City.
70% of the affected residents need to sign off on your permit request. Copies go to: Applicant, Police, Fire, Transportation/City Sign Shop, City Clerk (original copy). Everyone needs to sign off, so the permit request needs to be in at least five days before the event (I'd go with a couple weeks to be on the safe side).
Don't forget to invite your council representatives!
See also: an article of a similar title published by Ed in AnnArbor.com
$40 fee to close a street