iPod Touch GPS and Software Suggestions Needed

Hello All-

I need some suggestions for some apps/pc software to go along with my iPod Touch GPS rig. I have an iPod Touch (actually it's my wife's) that I bought a Magellan Tough Case for, and it gives the iPod GPS capability. My original intent is to use it with some marine charting apps as a handheld backup chartplotter for my boat. It then dawned on me after looking in the iTunes Store that there are a lot of land maps out there as well. I'm thinking I can use this as a handheld GPS unit to recon jobs, search for points, etc. I have a couple of questions:

What would be a good app that handles Waypoints/Tracks pretty well? There are a lot of street navigation maps out there, but I'm looking for something that would lend itself to surveying. I'm kind of spoiled by my data collector transferring files into and out of CAD, so something similar would be great. Even better if I could find something that would convert the waypoints into state plane coordinates and an ascii file for import/export into and out of Carlson.

What about some offline georeferenced aerial images or georeferenced topo maps? I've seen some apps that connect in to Google Earth for some real time navigation, but I would prefer to have some maps cached on the iPod so that I don't have to turn on my Verizon MIFI. There's a 5GB data cap on the MIFI, and if I go over the limit it gets pricey.

I'm going to study up on Google Earth (GE) regarding the import and export of waypoints via a GPX file. That appears to hold some promise, because I would like to pick points in GE and send them to the iPod, and vice-versa.

Any help here would be greatly appreciated in advance.

Dale Yawn
Savannah, Ga.