HDRi

Links to free HDR imagery for lighting cg scenes can be found here:

Accustudio
-Lots of hdr images

Aversis
-A few free lightprobes

Bernhard Vogl
-Lots of high quality hdr panoramas

Deviant Art users images
-Some users have uploaded their own hdr images

Digitalin
-Chrome studio effect hdr's

Evermotion
-lots of hdr skies

Hdr labs
-Heaps of high res, high quality hdr panoramas here <--RECOMMENDED-->

ICt graphics lab
-A few hdr panoramas

Lightworks user
-A few free hdri maps

Open Footage
-Lots of high quality hdr panorams here <--RECOMMENDED-->

Orkron
-Hdri's

Paul Debevec
-Some high res low quality probes

Sachform
-Comercial site offering a few free trials

Studio hdri
-High res studio lighting :
Set one
Set two
Set three



http://www.unparent.com/photos_probes.html
- Lots of light probes here