These technologies are still in development, but here are some incredible developments that can convert a picture into a 3D image:

http://www.photo-to-3d.com/

http://make3d.stanford.edu/

http://code.google.com/p/libmv/

Some links to free 3D models, that are compatible (.blend file, or can be imported) with Blender:

http://e2-productions.com/repository/index.php

http://telias.free.fr/Models_menu.html

http://www.blenderwars.com/content.php?module=download

I came accross some more Blender 3D tutorials, that I thought were pretty good for beginners (they show pretty well how to use the interface):

http://showmedo.com/videos/series?name=blenderMoyesSeries001

Also, here are some more Blender video tutorial links:

http://www.ibiblio.org/bvidtute/

http://www.blender.org/education-help/video-tutorials/

And another good place to start:

The new Open Movie (completely open source) Big Buck Bunny has been released! It's only 10 minutes long, but as you can see, it's very professional looking!

If you're interested in learning 3D, specifically Blender, I came across this set of Tutorials that's formatted in a "class" kind of way:

http://www.gryllus.net/Blender/3D.html

It has videos broken down into different functions and tasks, so it makes it easier to find a specific thing that you're trying to figure out how to do. Seems like a good place to start learning Blender, and even has some "intermediate" stuff too.

Ever wonder how to make it look like a 3D object is moving in relation to a moving camera? For the effect I'm talking about, have a look at this:

http://3d-synthesis.com/movies/Lincoln_1961_02.mov

The car on the left is created in Blender, the car on the right is real.