maybe i have to rethink my situation:
i have to store user profiles for every particular list like sorting/filtering and stuff.
my idea:
updating the profiles (when sorting) in a FilterController and redirecting to the particular Controller
which represents the list (i.e. PeopleController.index) where the loading of the collection
(with the updated filter conditions) and rendering takes place.

right now my sorting looks like that:
class PeopleController < ApplicationController
  def index
    respond_to do |format|
      format.html
      format.js{edit_profile(List.find_by_name 'people')} # the filter/profile updates are ajax calls
    end
  end
private
  def filter
    @people = Person.find :all, :include=>[:towns, :documents], :limit=>@filter.items_per_page,
         :offset=>@filter.offset, :order=>@filter.order, :conditions=>@filter.conditions
  end
end

class ApplicationController < ActionController::Base
  def edit_profile list
    @filter = Filter.find_by_user_id_and_list_id session[:user_id], list.id
    if params[:page]
      @filter.paginate params[:page]
      @js_template = '/shared/paging/paginate'
    elsif params[:order] && params[:col]
      @filter.sort params[:col], params[:order]
      @js_template = '/shared/paging/select_row'
    elsif params[:items]
      @filter.itemize params[:items]
      @js_template = '/shared/paging/itemize'
    end
    filter # call PeopleController.filter
  end
end


that looks not very satisfying to me.
that's why i think about putting the list stuff into an own controller
for updating the filter/profile params. but then there is the issue
to make the Filter.update action able to call the particular filter method of the particular
Controller (i.e. PeopleController).

do you have an idea?