At work, I almost always have 1) RainyMood playing as white noise, and sometimes 2) some music/news playing on top of that.

Here is how I setup my audio players:

one local player, one web-based player

both local players

• gnome-mplayer — play RainyMood.mp3 — this is a very simple player
  (call it with the --loop option)
• Rhythmbox — play streaming news/music:
  • NPR
    • WBEZ — Chicago
    • WBUR — Boston
    • KCRW — Santa Monica, California
    • WNYC — New York city
    • WAMU — Washington DC (more)
    • KQED — San Francisco
    • WHYY — Philadelphia
    • WPR — Wisconsin / Ideas Network (more)
  • BBC World Service