GFXartist.com - excellent reference site for digital art and design tutorials
www.gfxartist.com/features/tutorials

Digital Art Source - opening the world of digital art
www.digitalartsource.com/index2.shtml

Renderosity - excellent resource for digital artists including galleries, tutorials and models
www.renderosity.com

3D Artists - the largest 3d art gallery available on the web
www.raph.com/3dartists

The Digital Artist - international resource for digital artists and designers
www.thedigitalartist.com

Epilogue.net - fantasy and sci-fi at their best
www.epilogue.net/index.html

Digital Art Museum - online galleries of featured artists
www.digitalartmuseum.com

Artmixer.com - free tutorials on painter, web design, image editing...
www.artmixer.com

Digital Art Tutorials - find the best free Photoshop tutorials on TutorialMan.com
www.tutorialman.com/digital_art/page1

3D Spaceships and Robots - website of Hungarian digital artist Janos Miklos
www.urhajo.tvn.hu

Warp-online.de - large selction of fantastic fiction, art & digital art
www.warp-online.de/index_e.htm

3D Nauta - science-fiction "The roman walls of Lugo", graphic trilogy. Past, present and future of a technological strength in English, Spanish, French and Deutsch (simultaneous translation) 
www.3dnauta.com

3D Putty - 3D models of office furniture, cars and technology items available in .max, .3ds and .obj formats. Growing 3D collection and realistic models viewable with interactive 3D
www.3dputty.co.uk