This bloke has built his own Orb using an Arduino.
It predicts weather at the moment, but theres no reason this couldnt do other things:
http://www.therestons.com/scott/blog/?p=29

Recently, I found some c# wrapper code for ambient orb developers.
So if your interested in working with the orb and know c#, then check out:
http://betterthaneveryone.com/archive/2007/09/22/orb-code.aspx

"[The Ambient Orb is] a groovy little ball that changes color in sync with incoming data — growing more purple, for example, as your email inbox fills up or as the chance of rain increases. Martinez realized he could use Orbs to signal changes in electrical rates, programming them to glow green when the grid was underused — and, thus, electricity cheaper — and red during peak hours when customers were paying more for power."

Read More about this Ambient Orb Story

Here is a video of my orb just cycling colours:

This just takes the Ambient Orb to the next level:

http://zedomax.com/blog/2006/12/22/zedomax-diy125-howto-make-a-music-syncing-light-orb-alarm-clock/

Check out the Video

This guy has made his own orb:

http://weblogs.java.net/blog/kohsuke/archive/2006/11/diyorb_my_own_e.html

"While it's not as pretty as the ambient orb, this is cheaper, and more importantly it's way more fun! If anyone is interested in the source code / schematic, I'd be happy to make them available"

Assuming that you keep your schedule in Google Calendar (and really, who doesn't these days?), you can link it up the Ambient Clock (via Ambient's "nationwide wireless network") to find out what your schedule is. Meaning, a quick glance will help determine when you have scheduled events (the block rectangles on the clock) and the clock itself will change color if you have an upcoming appointment. As of right now the Ambient Clock isn't actually in production, although there is an online beta so you can get a feel for the features and help the engineers decide certain aspects of the build.

http://www.ambientclock.com