I know this isn't the best unit for expedtion type travels but the TomTom Nav5 I use on my Treo has a surprisingly complete inventory of otherwise unseen county roads and such. If anybody is looking for a cheap alternative or good turn by turn for your daily driver this may fit the bill.
Go to Toys R Us and they have it for $199 with 20% off. That takes it to $160 and if you ask for a "Are You Smarter Than a Fifth Grader" game piece and answer the question correctly you get another 10% of making it $144.
I believe this is in stores only.
:disclaimer: I don't work for TomTom or ToyrRUs. just passing on a good deal