Hi,
the httpclient library includes a custom file-based cookie storage.
I made a primitive drop-in replacement (myclient.cookie_manager = 
NSCookieManager.new) that uses OS X' built-in jar.

It works for getting stuff from Safari, but new ones I save don't 
propagate back there. Probably to do with the AcceptPolicy.

Anyway I thought I'd share it. The author's email is well hidden, so he 
probably doesn't like to be contacted. And I'm too lazy to create yet 
another Trac account. So see below.

http://dev.ctor.org/http-access2/

require 'osx/cocoa'

class NSCookieManager
  attr_accessor :cookies_file

  def initialize(file = nil)
    @cookies_file = file
    @jar = OSX::NSHTTPCookieStorage.sharedHTTPCookieStorage
  end

  def load_cookies
  end

  def save_cookies(force = nil)
  end

  def find(url)
    u = OSX::NSURL.URLWithString url.to_s
    a = @jar.cookiesForURL u
    d = OSX::NSHTTPCookie.requestHeaderFieldsWithCookies a
    return d["Cookie"]
  end

  def parse(str, url)
    u = OSX::NSURL.URLWithString url.to_s
    d = {"Set-Cookie" => str}
    a = OSX::NSHTTPCookie.cookiesWithResponseHeaderFields_forURL(d, u)
    @jar.setCookie a.shift
    raise unless a.empty?
  end
end

-- 
  Tobias Weber