Musical instruments for playgrounds http://www.tidewater.net/~xylojim/childrensmuseum.html

Aeolian (wind harps)
http://soundscapesinternational.com/index.htm

cool playground instruments for sale
http://www.freenotes.net/

Dennis Havlena : northern michigan instrument designer
http://edcen.ehhs.cmich.edu/~dhavlena/

National Reso-phonic Guitars : makers of fine resonating guitars
http://www.nationalguitars.com/index.html

Brad's Page of Steel : devoted to acoustic and electric lap steel guitars
http://www.well.com/user/wellvis/steel.html

Steel Pan Tuning : a handbook for steel pan making and tuning
http://stockholm.music.museum/pan/tuning/contents.html

Music House Museum : museum of mechanical musical instruments
http://www.musichouse.org/

private collection of stringed instruments           
http://www.home.earthlink.net/~minermusic/m_two.htm  

incredible collection of instruments for sale
http://www.mhs.mendocino.k12.ca.us/MenComNet/Business/Retail/Larknet/Catalog

great woodworking supply site
http://www.cs.cmu.edu/~alf/en/en.html

materials for instrument building
http://www.rogo.com/folkstuff/

interactive chart and chord diagrams
http://geocities.com/SoHo/Museum/1882/harpchor.html

site relating to various tunings
http://geocities.com/SoHo/Museum/1882/music.html

website devoted to polytonic chords
http://users.erols.com/wbeachy/

site with chord diagrams and audible tunings
http://geocities.com/SoHo/Museum/1882/harpchor.html