Here are some useful Earth Images to use.

[WingedOne]

Should be useful in case anyone needs to do models of Earth.
http://www.earthobservatory.nasa.gov/Newsroom/BlueMarble/

[Codexus]

Wow! They have it at 21,600 by 10,800 pixels resolution. Do you think that'll be enough? ;)
(Edit: That's even more than that 21,600 by 21,600 for each hemisphere!!!)

Great link!

[Muvlo]

Wow, great link. Thanks WingedOne!! :D