accepts_nested_attributes_for as Rails 2.1.0 plugin (or equivalent)

Question

I've developed a Rails app under Rails 2.3.5, and have made use of accepts_nested_attributes_for. Now I come to deploy it, I find my deployment environment is Rails 2.1.0 with no scope for upgrade. Obviously, 2.1.0 doesn't have accepts_nested_attributes_for.

Is there any way I can get the nested functionality under 2.1.0, as a plugin, say?