Try an iPad and have more big screen fun
[IMG]http://farm5.static.flickr.com/4018/4582138537_8c79804314_m.jpg[/IMG]Lots of great comments. I sometimes print out google maps using the advanced no highways settings and drag the road around to where I want to go and print. Unfortunately, you cannot do this on an iPhone (or iPad for that matter). The iPhone works great for a quick where am I but doesn't do very well if you have traveled for hours and are now in a location without a data connection (frequent).
When I purchased my iPad I couldn't wait to get it on the bike. The screen is huge versus the usual GPS units. I wrote it up here. [url]http://www.henshall.com/stuart/2010/05/05/motorcyling-with-the-ipad-better-than-a-laptop-or-notebook-for-certain/[/url] One thing the iPad does do well is retain the map. I'm yet to "lose" having access to the map on it although my wifi version won't give me location if my mobile hotspot can't find good old AT&T. The 3G version will cure the location and has the potential to be a very effective GPS - although note you can't see it in the sun. Mapquest can provide turn by turn but not yet in an ipod format. iPhone upsized.
Of note Nokia launched their Ovi Maps and these are downloaded to the phone. Thus a connection is not necessary for directions.
So.... a dedicated bike GPS unit is definitely still the best choice, although if you can read a map and like to wander... these phones are getting pretty good. The iPad also provides all the satellite view, hybrid views, etc. and can offer details on the hotel etc too and a movie in the tent.