My model includes and Account with 0..n Feeds. I have a form that contains N number of these: <input id="feed_url" name="feed[url]" type="hidden" value="http://images.apple.com/main/rss/hotnews/hotnews.rss" /> <input id="feed_url" name="feed[url]" type="hidden" value="http://images.apple.com/main/rss/hotnews/pr.rss" /> .... When this form is posted, what is created is something like this: {"feed"=>{"url"=>"http://images.apple.com/main/rss/hotnews/hotnews.rss"}, "commit"=>"Create", "account"=>{"service"=>"jabber", "action"=>"create", "controller"=>"feeds"} So the problem is that I''ve got an arbitrary number of feed[url]''s that will be posted. These will be created new, and so do not yet have any Id''s associated with them. I can''t figure out how to handle this situation with rails, and yet it seems like a common thing. The form I''ve shown above will post something like feed[url]=blahblah&feed[url]=otherblahthis. Under webwork (to compare) this would automatically be converted into an ArrayList containing each separate Entry, which could then be set onto the Account object. (I know that I can manually make input fields that are named feed[1][url], feed[2][url] etc. But I''d prefer to use the rails tag functions.) Is there a way to do this under Rails? Thank You