The RFM12B modules from Hoperf are small, cheap and offer a lot of features.
But their size has a slight drawback: both the SMD modules and the through-hole ones have 2mm pitch instead of the standard 2.54mm (100mil). This makes them incompatible with breadboards or prototyping PCBs. That is why I needed to make a little board which could hold a module and provide a standard sized header.
I chose the SMD version because this does not require an extra connector and the final assembly is smaller.
Below are some more pictures of the results and an archive containing Eagle files and PDFs to make your own.