How do you get the effect of a round orb in a picture like you see on stadium pictures?

I am new to the Good digital camera world. i got a nikon d70s, and am wondering how to get that effect and what other kinds of effects there are for SLR cameras? Im looking for a lense that would make a picture like this --------->http://bioweb.usu.edu/tag/images/invesco...

also the view like this, http://www.stadiumpanoramics.com/images/...

thanks for the help with this. any websites that have good info would be great as well.

The first shot was taken with a diagonal fisheye lens. For a Nikon, they run between $500 and $1,000 US.

I am not sure that I agree with the others that the other could be stitched together with photoshop. It's hard to tell, but it doesn't seem like it. You would notice the stitching in the people. Most likely it was a panoramic camera. Big bucks.

The first one looks like a fish-eye lens was used, the second one appears to be a click, turn, click, turn, click until you have taken all the photos from one side to the other, then combine them in Photoshop or whatever your choice of software is.

as far as i can tell, the first lense is a fish-eye lens, and the second is either multiple pictures pasted together well, or they used a panoramic lense (sorry i can't give details, i've only used a good friend's!)

I agree with the others but I'd like to add something else.

First is wide-angle or fisheye lens. Fisheye is a pretty freaking expensive lens from reserach I've done. If memory serves me correct it's like $700 alone for the lens.

2nd - panaromic or photoshopped multiple images.