There is a problem with InvalidAuthenticityToken errors that are raised in the methods for the in_place_editing plugin. This happens in Rails 2.0.2 (and possibly earlier versions). It's because there is no authenticity_token sent at all. You can apply this patch until there is a new version out.

If you have something like this:

<%= in_place_editor("title", {:url => url_for(:action => "update_title" ...)}) %>

the update_title method will throw an error. Apply the patch to make it work.