Came across this earlier today – a new plugin for the in-place edit controls
http://os.flvorful.com/super_in_place_controls

You can see a demo at http://os.flvorful.com/super_in_place_controls/demo

I haven’t looked at the code yet but it’s supposed to be fully compatible with Rails 2.0 and has some extra features that I like such as resizable textarea inputs, support for radio and checkbox collections and select boxes. The syntax looks pretty clean too.