Violins

http://www.elidatrading.co.uk/

http://www.londonviolinstudio.com/violin-workshops.html 

http://www.owenmorse-brown.com/pochette.htm

Digital Painting Tutorials

DVD training 5: Chaos & Evolutions
http://idrawgirls.com/
http://enliighten.com/
http://www.floobynooby.com/ICG/artvalues.html
http://www.ctrlpaint.com/digital-painting-101/

Piano teachers

http://www.pianolessonsnorthlondon.co.uk/
http://www.londonjazzpianoschool.com/page14.htm 
http://www.walterfabeck.com/  (teaches composing too)

http://www.davefrankjazz.com/skype/skype.html
http://stevenixonmusic.net/lessons.cfm