An old project of mine. Some two years ago I made this design which was part of the product range of my old company. It is a full Uno plus some extras fit on the very much favoured by me PLCC-68 format (roughly 1"x1").
Banguino is available from my Tindie store: https://www.tindie.com/products/KnivD/banguino-module/
Just like my newer Configum module it fits into a PLCC68 socket. In addition to the standard Uno it offers an additional 10-bit I/O port, micro-SD slot on board, USB connection, power supply, and pin-compatibility with all other modules (follows my own DTX2 standard pinout as described here several years ago: http://dimitech.com/downloads/an0003.pdf).