Hi
I work for Ciseco a small company based in Nottingham, UK. We make Radio modules, many people know us for the
XRF module.
Last month we added the
SRF to our radio family. The SRF is a small surface mount modules that is physically compatible with the RFM12B foot print. The SRF can be used over a UART or SPI bus.
I've designed a TinyShield that will take our SRF module or a Hope RFM12B module.

I wanted to post the here and see if there was interest in this as a product.
The PCB has the SRF connected to the UART by default, but there are cut track's and solder pads on the under side that can be used to swap to the SPI bus.
To stay within the main board size this would be a top shield and not stack through. The SRF by default has a chip antenna this would extend out over the Tiny's foot print to the purple box, however this can be removed and a wire whip use instead.
Matt