I know it's possible - because it's Amiga

Discounting a Rejuvenator or Phoenix board has anyone achieved this?
As far as I am aware there are no plug-in upgrades to achieve this.
A solution I am thinking of is to make some kind of adaptor for the DIP style Agnus to a PLCC style socket, to allow a "MegaChip" style upgrade to be used.
Does anyone have any ideas?