PTG Chapter Sites
National office of the Piano Technicians Guild: http://www.ptg.org
Seattle Chapter of the Piano Technicians Guild: http://users.iglide.net/dpetrich
Canadian Piano Page:  http://www.canadianpianopage.com

Piano Stores and Dealers
Classical Grands  http://www.classicalgrands.com
Fandrich Pianos: www.fandrich.com
Here's a store I haven't been to: http://www.secondhandpianos.net
New Italian upright with the touch of a grand: http://www.cerratopianoforti.com
Shopping for pianos?  http://www.chicagopianos.com/wantedposter.htm

Ads and Advertising
List yourself in a new national directory: http://www.pianofinders.com/technicians/locatetech.htm
Place an ad on this site:  http://www.piano-classifieds.com
Connecting people and pianos around the world: http://www.pianofinders.com Karen E. Lile

Historical Temperaments
Lehman: U.Mich professor Bradley Lehman offers here a keyboard temperament analyzer/calculator, along with cogent explanations of the need for temperament.
Temperament Offsets: Researched by Willis Miller for Avery Todd, an exhaustive list of offsets for historical temperaments.
All About Temperaments: Excellent introduction to historic temperaments.
J.S. Bach Tuning: detailed scholarly attempt to determine how Bach tuned his instruments.
The Well-Tempered Clavier: Fictional, entertaining and instructive account of all the Preludes and Fugues.
Music History timeline
I have a website devoted to historic temperaments, taking Jorgensen and making the tunings graphically understandable, with a lot of modern well temperaments also. This site is being accessed by a lot of Verituner users, and it would probably be a good addition.  Jason Kanter: jkanter@rollingball.com   also jason.kanter@wamu.net in my day job
http://www.rollingball.com

Tools and Supplies
HobbyLinc CA Glue: Good source for CA glue for loose tuning pins.
www.pianosupply.com/: International Piano Supply, in Astoria, OR.
Pianotek Tools
Spurlock Specialty Tools  Bill Spurlock:  SpurlockTool@cs.com
Mother Goose Tools
Pianoforte Supply House: located in B.C.
Balaams-Ass, piano supplies catalog based in Tennessee
Renner USA site map
Renner Tool Catalog
Pianophile: Canadian distributor of piano tools, parts and supplies.
Arledge Music Wire: for ordering piano bass string replacements.
Two unusual lubricant sources: www.syn-lubes.com and Nyelubricants
Ingenious piano lifting device:  http://www.televateur.com

Piano-Related Software
Pscale and other computer tools for piano technicians. Calculate touchweight, stringing scales, and more.
www.oppor-tune-ist.com for ScaleMaster, which Joe Garrett praises
Accu-tuner: Sanderson's homepage

Of Technical Interest
Piano Serial Numbers 1: The "Blue Book of Pianos" -- serial numbers and manufacturing dates. Not very up-to-date, and somewhat inaccurate in Steinways.
Cents to Hz Chart: Online calculator of frequencies and cents offsets.
5 piano acoustics lectures. The five lectures describe the underlying physics upon which all detailed modeling of piano tones must be based. Extraordinarily useful.
Piano Technology Practice Exams: Online multiple choice tests in piano technology.
TuneLab_Users: Yahoo group for users of Bob Scott's TuneLab
Digital Piano Shootout: Excellent sound samples of MANY digital pianos. The one called "The Holy Grail Grand Piano" is tuned to Paul Bailey's well temperament.
The pianotech Archives: look up anything in the pianotech discussion history.
piano FAQ: A collection of information gathered from rec.music.makers.piano about purchasing and maintaining pianos.
Piano on the Net: Online piano lessons!
Sunhawk: Sheet music store
Tuning by Jorgensen: Summary of the contentsof Jorgensen's "big red" tome.
Converts pianos into desks:  http://www.pianodesk.com/index2.htm
David Stanwood's Touch Weight Calculator at: http://www.stanwoodpiano.com/Calculator.htm