Perhaps the best way to follow me is with this link to my full-size Google Map entitled "AT Map for Stats". (The map address is http://g.co/maps/upzkv.) The map will be blank until March 13, 2012, when I will take my first of 5,000,000 steps northward. I estimate the trek will take me 5.5 months to complete.
Once you're at the map page (and after I've begun my journey), you'll see red teardrop markers at the beginning and ending positions of each of my recorded tracks (in blue). Clicking on these markers will reveal the date it was recorded. Alternatively, you can scroll down the panel to the left of the map and click on one of the dated icons to zoom to that position. (If the panel is hidden, show it by clicking on the show button.) In this way you can follow my progress. Unfortunately, I will be unable to keep my phone's GPS unit on all the time (doing so would suck my battery dry), so most of my tracks will be quite short in length unless I'm coming into town and know I can recharge the phone after a day of GPS tracking. I plan on recording my position at least once a day, but I imagine I'll also record the coordinates of special places to which I'd like to return with my family. Therefore, this map will typically show little snippets of my path, not a detailed step-by-step progression.
Some of my friends and family are charting my progress on the Appalachian Trail National Scenic Trail Map. If you want a copy of this map, you can purchase it from the Appalachian Trail Conservancy (ATC) for about $3, or you can download it from the National Park Service. If you download and want to print the map, try changing the Page Scaling on the Print window to "Tile larger pages":
For a really good interactive map, check out the Appalachian Trail Conservancy's (ATC) Interactive Map. This map shows not only the entire AT, but also images of scenic vistas and shelters along the way. You can zoom in to view road crossings and which towns I'll be coming through.
Below is the embedded map of my hike, but the Trail is just too long to fit into the tiny window. You're probably better off just clicking on the full-size map.
View AT Map for Stats in a larger map