List of White Noise / Ambient Sounds to stay focused and increase your productivity

One thing that has helped me stay focused is light background noise and sounds.  It helps drown out possible interruptions and people tend to not bother me with headphones on :). I keep it mixed up by rotating several difference sources; here is a list.

1. myNoise.net - Large collection of hand recorded sounds which are great quality.  Each sound has a mixer with presets that slightly changes the sound and can be 'animated'. 
2. A Soft Murmur - Easy to adjust volumes of different sounds to create your own mixes, with a master volume.
3. Noisli - Good selection of different sounds that can be individually controlled.  Love the railroad track.
4. Coffitivity - Cafe and other environmental sounds.
5. Rainy Cafe - You have Rain, and you have Cafe, simple interface so adjust the volumes how you see fit.
6. raining.fm - Rain, thunder, and lightening, can be mixed together.  The break and sleep timers are a nice addition.
7. ambient-mixer.com - Community driven noise and sound collections, large library.