These are some of my favourite sites on the web:

Photography

Wetpixel Dedicated to underwater photography and videography.

Rob Galbraith Digital photography news, reviews, tutorials and discussion forums for pro photographers.

Dpreview Where you'll find all the latest in digital photography and imaging news. Technophile heaven.

Luminous Landscape You might need to search a little, but there is a treasure trove of information to be found on this site.

photo.net One of the largest and oldest photo sites on the net, photo.net has information on techniques and equipment, plus a huge community of photographers.

Photographers

Alex Mustard Underwater photographer extraordinaire.

Chris Groenhout Great pics by Australian photographer Chris Groenhout, plus info on photography.

Eric Cheng Multi-talented underwater photographer and IT guru.

PhotoLinks - The Photography Network Links page.

Wags & Kelly's High Definition Underwater World Western Australian underwater videographers. Superb clips and underwater video podcasts.