Paperclip with external url and asset_host?

I’m trying to get Paperclip to work with asset_host and have totally
failed to do so.

The idea is to use asset_host to specify the url that I want to use for
my image hosting ( so that link helpers
will use the image host location instead of the local file system.

This works really well and in truth I’m totaly blown away by the power
and simplicity of Rails but for the life of me I can’t get Paperclip to
play ball.

Having delved a little into the Paperclip source (scary!) I find that
the File class is used to do the io streaming and I’ve kinda got an
incling that I might be able to make use of this knowledge somehow but I
really need a pointer as to how to proceed with this.

I notice that there is an S3 option and also wondered if that could be
adapted to be used to in some way?

Any ideas would be greatly appreciated