I've used Bitmap a fair bit on my iPhone 3GS... It's good for my old Oziexplorer maps (a lot are Tassie topo 100k and 25k maps that I had as JPG files and converted to ozi files)
I found Bitmap a bit buggy for saving long routes, it often froze up and crashed when the route got to around 2000 points (on the iPhone 3GS)... I tinkered with quite a few other appz and the only one I found that suited me was:
It's a bit of a steep learning curve to get the most out of it, but I think most mapping applications are like that...
I use it on my PC and iPhone.. They have Android and WinCE versions too.... All versions are free I think, except for the iPhone/ipad version which is $7:50 now, it use to be free but they had issues with Apple (it's free if you phone is jailbroken)
You can buy state topo maps, and hema 4x4 maps through it, but they aren't cheap... around $150 for a license to use a state map-set on 2 PC's and 2 mobile devices I think...
I use the free "Aus Topo250"
maps, they show most the roads and tracks down here, but not all..... I'm too cheap to spend the money on the 100k and 25k maps.... If I need more detail I open Bitmap and use the maps I have in that... (and leave Memory-Map in the background recording my route)
It records the route as a GPX file, I upload them to "Ridewithgps" to embed in ride reports... (look at the links in my sig for embedded examples, or> http://ridewithgps.com/trips/970892
(I usually save a KML version of the route from Ridewithgps also, I open, then save them, in Google earth, it's handy for route planning)
The mobile versions of MM use GPX files, but the free PC version wont open them, you have to pay for a $125 upgrade to be able to open them (the upgrade also allows you to import and calibrate other map types and images)... Being cheap I use a free utility, GPSBabel, to convert the GPX files into a MMO (memory map overlay) file, which can be opened in the free PC version of MM... (I like to load all my routes into th PC version so I can see where I've been and plan future rides while looking at the same maps I use on the road)
You can download "map packs" to pre-load onto the phone... or MM can download them as you need them.... (if you have phone reception) ... You can just scroll the map around while you're at home so it downloads the areas you need for a trip...
I wanted to pre-load the whole free "Aus Topo250" map of Australia onto my phone so I don't have to rely on mobile reception or pay for data costs...., so on the PC software, I zoomed out as far as I could, then just dragged the map around till it downloaded the whole map of australia, then copied the 850meg "Topo250-2.qct", and "Topo250-2.qc3" files from "C:\Maps\DMS\Australia\Topo250" (the folder where the maps are stored), and saved them onto the iphone through iTunes... (there's tutorials on how to do this that probably explain it better than I can)
I never really worked out how to pre-plan routes in the Memory-map PC app.. I just use RidewithGPS to create routes, then save them as GPX files to load onto the phone through itunes...
MM on the iPhone:
(I leave all my old tracks/routes on the phone, I just set them as orange so they blend in with the roads on the map... Handy for when I've used unmapped roads, it's basically like adding roads to the map)
The PC app showing some of my tracks: (the screen-shot quality is pretty poor, fairly compressed, I didn't want to load this thread up with HUGE images)
A couple of random areas to show the detail of the free "Aus Topo250" maps:
A years worth of tracks/routes, most recorded on MM, then used on Google Earth:
No doubt there's better applications out there, but, as a (basically) free mapping solution this works for me, it runs well on the iphone, which is also playing music ALL the time, and it continues running in the background if you want to use other applications at the same time...
(BTW, I'm not a fan of Apple, the iphone is a hand-me-down from a relative that works for a phone company, they upgrade every few months)