I have decided to play in the world of GPS modules. I have read the GPS Buying Guide from Sparkfun, but still am not sure which unit I want to go with. I am leaning toward the LS20031, do any of you have any experience with GPS modules? Any advice you would like to add to the chiphacker community?
I recently purchased a couple of GPS modules for a project I'm working on. You didn't specifically mention Arduino, but I bought the GPS logger shield from Adafruit with an EM-406a module. I'm not using an Arduino, but I figured it was a compact solution that had two things I wanted (GPS and removable storage). The EM-406a had no problems getting a satellite lock inside my office. I also got the Copernicus DIP Module from Sparkfun so I could breadboard with it. No problems so far - just read the datasheet and remember to pull XRESET and XSTANDBY high.
u-blox makes the best ones, but they are expensive. They are used by the military and government agencies because of their performance. I didn't have any problems with one of their modules on a home-made PCB, interfaced to a 16F88 PIC. It works indoors.
There's lots of detail about building a GPS to SD Card Logger here. It uses a PIC but you may be able to make alterations as you want.