DESIGN 2.0 - Update

You'll find many more cool apps like the ones in the list below when you search the web for them systematically - or accidentally, through Stumbleupon, where they are deliciously over-represented.

Ajaxsketch - Create drawings & diagrams
Betterdesktop - Share usability tests
Browsershots - View thumbs of your website in all browsers
Bulletprooflinks - Share tutorials, tools & templates
Buttonator - Drag, drop & share web buttons
Colorblender - Color picker & matcher
Colorcell - Find beautiful color combinations
Colorschemer - Explore color schemes
Colourlovers - View, are & review color schemes
Colrpickr - Color picker
CSSbeauty - Submit & share well designed websites
Dontclickit*** - Clickless interface
Flashpaint - Draw & share pictures
Flickrlogomakr - Make Flickr-like logo in a second
Flowermaker - Design flowers
Fonttester - Compare fonts side by side online
Gogofrog* - Create & share your 3D web page
Kancept - Submit design concepts and have them reviewed & rated by other users
Linkgrab - Submit & share links on design
Mockingbird - Collaborative design (Stealth)
Multi-touch* - Handy interface
Netcocktail - Share color schemes
Neurosky - Bionic interface technology
OK-cancel - Collaboration on interface design
Picture2life - Edit pics online
Pixelgroup - Draw anything with others
Rasterbator - Creates rasterized images
Sketchup - Create & view things in 3D
Snipshot - Edit pics online (a.k.a. Pixoh)
Typetester - Compare screen type
Webbrush - Collaborative drawing, charting, etc
Wufoo - Build & host forms

Italic = new. Update 061221, 070119.