We regularly run workshops for soundart and soundscapes production and play.
Here are some of the links we use.
If you find any interesting sites not listed here, please do let us know!

What are soundtoys?
“Soundtoys may take the form of art, games, generative music, interactive environments, shockwave movies, etc.They could be described as "new audio visual experiences", or multimedia experiments which explore the parameters of our new media world. They might be described as the fusion of audio and visual output through new technologies made available for the internet.” www.soundtoys.net

Most famous experimental musical instrument, the Theramin was made in 1919
Experimental music was first introduced to us by John Cage and Frank Zappa around 1960’s
1998 www.soundtoys.net was setup for people who wanted to mix the experimental with computer based programming
1998 Australian and American universities started studying and running sound art and sound science courses, where SoundToys started to be featured, along with audio acoustics etc.

Physical Soundtoys, otherwise know as “experimental musical instrument” or “sound sculpture”

iOS apps
Synth Pond Lite - https://itunes.apple.com/us/app/synthpond-lite/id296468149?mt=8&ign-mpt=...
Sonoria - http://www.artisopensource.net/network/artisopensource/2011/04/30/sonori...
Kalevala - http://mroliverblank.com/kalevala/
Vector Park - http://vectorpark.com/
SingingFingers - http://singingfingers.com/
Sonoria2 - https://itunes.apple.com/us/app/sonoria-2-a-voyage-into-noise/id43460259...
Dropophone - https://itunes.apple.com/us/app/dropophone/id376771022?mt=8

Android Apps
Harp - https://play.google.com/store/apps/details?id=cc.openframeworks.Harp
Color Sound Machine - https://play.google.com/store/apps/details?id=com.versuspad.colorsoundma...

Online Soundtoys
Grotrian Pianos - http://www.grotrian.de/en/act_pianolina.html (flash)
Windowsill - http://windosill.com/ (flash)
Sequencer Player - http://rebeccanesson.heroku.com/sequencer.html (flash)
NoiseGames - Lots of mini soundtoys to play with here! - http://www.noisegames.com (flash)
SoundToys - http://www.soundtoys.net (flash)
Strange Sounds Map - http://www.seektress.com/ssounds.htm
Using the Fibonacci Sequence to produce sounds - http://musicalgorithms.ewu.edu/algorithms/Fibonacci.html (flash)
Using the Topography of the Moon to produce sounds - http://wms.selene.darts.isas.jaxa.jp/selene_sok/about_en.html
Glow Doodle - http://scripts.mit.edu/~eric_r/glowdoodle/ (flash and webcam required)
Listening Games and Soundscapes - http://www.exploratorium.edu/listen/online_try.php (flash)
Online keyboard - http://www.iquilezles.org/apps/soundtoy/ (flash)
Soundwalk game - http://www.addictinggames.com/action-games/sound-walk-game.jsp (flash)

And for those of you who want to have a research into some soundart artists check out...
Naomi Kashiwagi
Brian Eno
John Cage
Chris Watson
Wassily Kandinsky
Steve Reich
Delia Derbyshire
Peter Howel
Ron Granger

Now for the more geeky ones...
First what is an algorithm?
A process or set of rules to be followed in calculations or other problem-solving operations, esp. by a computer. Typically, when an algorithm is associated with processing information, data is read from an input source, written to an output device, and/or stored for further processing
Think of it as a process the computer does, to do something that requires analysing and calculating something.

Apps for computers
Photo Sounder - http://photosounder.com/
Paint2Sound - http://flexibeatz.weebly.com/paint2sound.html
Sonic Photo - http://www.skytopia.com/software/sonicphoto/
Bitmap Player - http://victorx.eu/BitmapPlayer.htm
*The program creates images of sounds (use the Fourie tab) and sounds of images (use the Inverse Fourie).
Color Tones - http://victorx.eu/ColorTones.htm
Coagula - Bmp to wav - http://www.sonicspot.com/coagula/coagula.html
Tune Toys – GIF to MIDI - http://nosuch.com/music/gifjam.cgi
AudioPaint – Image to Audio - http://www.nicolasfournel.com/audiopaint.htm
Paint2sound - flezibeatz.weekly.com/Paint2sound.html
TalkBackToBasics - for those Mac Makers – http://www.wizardmaster.com/bludgeonsoft/tbtb/index.html
Sonic Inspiration Blog - http://www.everydaylistening.com
What is Sonic Bitmap Encoding - http://www.gramschmalz.com/encoding-images-as-sound-decoding-via-spectro...
Range of programmes from the Bitmap Player - http://victorx.eu/index.htm#pics

Where to hear more?
http://radiolive.wordpress.com/art - list of online streaming links
Community radio stations in the UK, such as http://www.soundartradio.org.uk http://resonancefm.com and http://www.basic.fm/
By searching online using keywords such as “soundart” “audioart” “experimental audio/music” “soundscapes” “soundtoys”

Free Software for Music Creation List
Keyboard sampler - http://www.soundplant.org/
Make your own Oscillator - http://www.sciencebuddies.org/science-fair-projects/project_ideas/Elec_p...
Easy online lessons on Music Theory - http://www.8notes.com/theory/
Audio theory, info on samplers and how to burn a cd etc. - http://www.planetoftunes.com/digiaudio/index.html

It's come to that point in a project where you need a little backing music, or a sound effect and a sample to finish off your audio or video work, and it's not as simple (unless you have wads of cash lying around) to use chart music or something off your mp3 player.

Here's a few links to where you can find free to use music and audio - just check the details on the licences of how to use them.

What is Creative Commons Music and where to find it - http://creativecommons.org/legalmusicforvideos
Free Music Archive - http://freemusicarchive.org/curator/creative_commons/
Download, Sample, Cut-Up, Share - http://ccmixter.org/ and search - http://dig.ccmixter.org/
Found sounds, foley and more at FreeSound - https://www.freesound.org/
Creative Commons Case Studies and Examples - http://wiki.creativecommons.org/Audio
Search Creative Commons for different types of digital media - http://search.creativecommons.org/
Music with freeflowing player - http://www.jamendo.com/