I'm leaving on a road trip through southern Florida later to day, and am hoping to not have to take my laptop and instead just use my N800. To do this though I'm looking for a good consumer oriented mapping program that I can use on the N800. My basic needs are for a old school Streets and Trips type of program.

I need:
Street level maps for the state of Florida
Something that can be downloaded onto a small card. I'm using one 512 card and one 256 card while waiting for my 16GB card to arrive.
Something that will work completely independent of internet access (once the initial download is complete)
Something that works by entering in street addresses, and not GPS coordinates.
Ideally it would offer Point A to Point B routing instructions that work without internet access or GPS also.

So does anything like this exist?

Go out and buy a 2 gig card to get you by, and Maemo Mapper should do nicely, I expect.

Maemo Mapper seconded as your best bet.
I've got street view maps of a few big cities, most of the motorways and my home town, from both google maps and the odd bit of google satellite view in about 179 MB.

http://maemo.org/downloads/product/OS2008/maemo-mapper/

The only problem might be in browsing by street address - in order to look up streets / postcodes it consults an online directions server.

I believe that you can use routes from other software with it - so you should be able to keep them off-line.

Wayfinder ?

I've tried to use Maemo Mapper before, but all the instructions seemed to center around using GPS? I feel stupid in that even after reading the quick start, I can't figure out how to download maps by geographic area. I'd love if someone could point me to a quick start for dummies type of thing. I'm leaving in about 4 hours, but I'm at work so I've got only about 15 minutes total that I can dedicate to this.

Unfortunately this trip came up spur of the moment (just found out I was leaving late last night) so there wasn't a lot of time for prep.

I've got an n800, so no GPS.

Quick-tips (since I'm at work too):

Grab a few maps automatically to find areas you want to zoom in to.
Menu -> Maps -> select Auto-Download
Then feel free to turn the auto-download off after you've got some base maps to start from.

To download specific geographical areas, centre the display on, for example, London - stay zoomed out so that the whole area fits into the screen.

Menu -> Maps -> Manage Maps
(There are options for downloading maps by area or along a route)
Select the Zoom tab and choose which zoom-levels you want to download. You probably won't need to go all of the way down to level 1 since at that level you don't get much more benefit, but there'll be a load more maps - I found around level 4 tends to be as far as I usually need to zoom.

Download the maps and you're done.

Thank you! That is perfect. Really appreciate the help.

Further advice if download size has potential to be a problem: skip sizes; I (for large portions of the areas I've grabbed) got sizes 3, 5, 7, 8, 9, etc.

Particularly the next-to-lowest (4 in my case) is a lot of data, so if you can do with that skip, it helps. When you get up to larger sizes, there's no point skipping.

I've tried using Mapper to download a few maps, but I always get a message that says, "Map failed to download". Wifi is strong and it downloads, but when it gets near the end, it spouts the message out. I've been more reliant on Wayfinder now.

I still have Mapper on my N800, but it's just gathering dust.