Offline maps for GPS on Android without a need for a data connection

To follow up on my recent post about Navit, a cross-platform map and GPS program that you can use on your laptop when on the road, I did a search for map/GPS programs on the Android platform that do not rely on a data connection. Like I mentioned in my previous post, I sometimes travel to locations where I do not have cellular signal (like in the mountains), which render Google Maps and my phone's default navigation software useless. GPS signals are usually available as long as I'm outdoors (based on my personal experiences), so I hope to rely on a device with a GPS receiver with maps stored on it.

For the Android platform, I discovered MapDroyd and CoPilot from this thread. MayDroyd makes use of OpenStreetMaps like Navit and tangoGPS, and hence is free. CoPilot costs money.

To store map data on my phone, I'm going to need to buy a bigger micro SDHC card (32 GB?) since the entire planet data is over 6 GB and the Americas is over 2 GB.