The Whole World in Your Hands
At NASA's Blue Marble web site there are really big images of the whole earth. REALLY BIG IMAGES!
Don't get fooled into dowloading the laughably small 2048 by 1024 pixels (1.8 MB TIFF) image, or even the tiny 8192 by 4096 pixels (26.5 MB TIFF) image. And don't even think about just settling for the medium size 21,600 by 10,800 pixels (173.5 MB TIFF) image.
Go for the gusto - the big dog - the holy mother of all earth images! It's a whopping 43,200 by 21,600 pixels (642 MB TIFF)! It's so big you gotta get it in two seperate hemispheres!
You can get them all here. The last two are the big ones.