Tynsoe's Geek Tool just keeps getting better and better. But don't let the name or screenshots fool you, it's as useful for home automation as it is for watching console logs. Here's how I use it:

• Every few minutes, I see an updated image from the webcam that keeps an eye on my dog, Scooter.
  
• If I'm on my home network, I can view the spool log for my laser printer so I know when my documents have been printed.
  
• I haven't quite perfected this yet, but I'm working on getting my XTension log showing in a window too.
  

The best thing about Geek Log is that it's a system preference, so you don't have to muck around with an extra application, and it has a menubar extra that makes it every easy to switch between different sets of windows, force a refresh, or turn the whole thing off.