Which are the OS X Dashboard Widgets you can't live without? I don't use widgets that much, but one particular widget makes the dashboard useful to me. That's iStat


  iStat Pro is a highly configurable
  widget that lets you monitor every
  aspect of your Mac, including CPU,
  memory, disks, network, battery,
  temperatures, fans, load &amp; uptime and
  processes. iStat Pro can do it all.


And it's FREE



Do you have one outstanding widget to share? How do you use it?
Please follow these simple rules:  


Please search for duplicate answers before posting. You can search
this question like this: inquestion:this iStat Pro  
Limit one dashboard widget per answer.   
Add a link to the website in the name of the application if possible (no direct downloads).
Tea Timer



It's simply a timer. Notifies with:


Sounds
Speech
Growl


Text completely customizable (food pictured). ready in can be changed to just in.