What is a good mobile mapping software?

[Jeff Duda]

If you aren't interested in trying MS Streets and Trips or Delorme Street Atlas AND you have one of the GRLevelX products, you can import road shapefiles into GR to view right in the software. If you find the right shapefiles, you can get just as much detail as the proprietary products and you can look at it while viewing radar! I know of the following sites that offer them:
http://www.meteor.iastate.edu/~slincoln/GRS/shapefiles/ (probably the most detailed, but also take more memory to use)
grlevelxstuff.com (you have to sign up for this)

Here's a screen grab from GR2 using the placefiles from the first source:
example in GR2
If you continue to zoom in, the secondary roads and city streets will begin to appear.

 

[James Hammett]

I like using the road shapefiles in GR while chasing as a road-verification supplement to Delorme but be sure to have plenty of RAM available especially if you split your GR into multiple panels. I have 2GB in my carputer and it's just enough for two panels before things bog.

 

[Adam Simone]

If you aren't interested in trying MS Streets and Trips or Delorme Street Atlas AND you have one of the GRLevelX products, you can import road shapefiles into GR to view right in the software. If you find the right shapefiles, you can get just as much detail as the proprietary products and you can look at it while viewing radar! I know of the following sites that offer them:
http://www.meteor.iastate.edu/~slincoln/GRS/shapefiles/ (probably the most detailed, but also take more memory to use)
grlevelxstuff.com (you have to sign up for this)

Here's a screen grab from GR2 using the placefiles from the first source:
example in GR2
If you continue to zoom in, the secondary roads and city streets will begin to appear.

This is what I do as well. I have my GPS puck connected to GR3 and use the map placefiles. I also have a separate GPS unit in my truck and my iPhone's Google map if I need more detail than what the placefile provides, but I think the placefile worked very well for me.