netduino plus 2 compatible gps/gsm module
I use a GPRS Shield from SeeedStudio and the GPS Shield from Iteadstudio (Just need to change the serial ports used so they play nicely together)

I initially trialled the "Netduino Driver For SeeedStudio GSM Shield" on Codeplex but now use the CodeFreak Out SeeedStudio GPRS Driver which is available via NuGet or as source code on Github. 

I use the NetMF Toolbox NMEA driver on codeplex with a couple of mods. When the serial port reports an error I flush the inbound buffer and I also return the Horizontal Dilution of position (hDoP)

(I would post the NuGet, GitHub &amp; NetMF toolbox links but don't have enough reputation points)

Bryn @ devMobile