tools

Various online craft tools exist, usually for colour planning or design generation. These are the ones I know about:

Needlework

Cross Stitch Charts from photos
My Photo Stitch a free service that takes photos you upload and gives you a cross stitch chart using (last I checked) DMC colours

Knots

Turk's Head Cord length calculator
http://turkshead.50webs.org/
Turk's Head Knot designer
http://data.oreilly.com/jallwine/knots/
Globe Knot Core Calculator
http://khww.net/gkcc.php
Turk's Head Design Playground
http://web.meson.org/crafts/TH/TH.html

Kumihimo Braiding

8 strand kongo gumi colour planner
http://www.lythastudios.com/123bead/kumiplanner.html
16 strand kongo gumi colour planner
http://craftdesignonline.com/kumihimo/
A colour planner for the 7-loop Spanish finger loop braid
http://www.islandlife.heliohost.org/cgi-bin/fingertips.pl

Spinning wheels in general tend to very expensive. Apparently, powered spinning wheels are very, very expensive. But if you (or someone you know) have the DIY spirit, you too can have a nifty powered spinning device (wheel part no longer needed).
http://www.glacialwanderer.com/hobbyrobotics/?p=79