I have a small waterproof topo map that I got from MyTopo. The quality is excellent. You could always buy one of their small maps to check the quality yourself before investing in a much larger map.
The MyTopo company (now owned by Trimble) has been buying paper USGS topos and making their own scans. They de-collar the scans and stitch them together with software. By doing this they can produce maps that cover the area you specify.
MyTopo also lets software developers display their topo maps as long as the public can view the maps for free. When MyTopo maps are displayed by 3rd party software then the maps have a watermark and the screen is required to show some MyTopo ads. The following link displays the MyTopo topos for a random spot in the Ocala National Forest of central Florida:
http://www.mappingsupport.com/p/gmap4.php?ll=29.174305,-81.922081&t=t2&z=15
OK, full disclosure time. I'm the developer of Gmap4 which is showing you the topo maps. The homepage has a FAQ and examples to quickly get you up to speed.
Although the printed MyTopo maps you buy are high resolution, the MyTopo maps you see online are
medium resolution. To see
high resolution topo maps online for anywhere in the USA except Alaska, open the above Gmap4 link and then in the very upper right corner click "t2 MyTopo" ==> "t4 Topo High".
Want to show your GPS data on the topo map? Sure, you can do that with Gmap4. Want to click the map and save your work as a GPX file? Yup, you can do that and more. Check out the features under the Menu button.
This project is part of my way of 'paying it forward'. Translation: Gmap4 is free for non-commercial use.
Gmap4 homepage:
Gmap4 = Google Maps + Free Topographic Maps + A Lot More
Enjoy!
Joseph, the Gmap4 guy