It came from this page, here's a couple more pics from there:
I was going to say that top shot could not have been a single exposure, but if you go to the website they explain how many pictures were combined for most of the shots.
A single exposure long enough to see the Milkyway will give star trails:

But are less noticeable on a wide angle shot:

Images taken out on the Anderson Mesa near Flagstaff, AZ. There's a telescope out there that a bunch of undergraduate schools share time on.
Funny that it never occurred to me to combine shorter exposures to avoid the star trails when doing sky images with my DSLR, since it's a normal thing to do when taking pictures through a telescope. It would mess up any trees or buildings in the shot but the sky would look great. Basically you take a bunch of exposures and line up the stars and add them together.
Like this one that was probably 20 exposures in different filters over 2 nights, adding up to 3 or 4 hours total exposure time:

I always wanted to take a picture of that, but never had a big enough telescope until the new one we got in '05, it's so faint even with a big telescope it takes hours of exposures to see all the details.