I just created a new website that I’m pretty happy about called Is My  
Computer On. It’s a new tool that anyone can use for free as long as  
they have a computer with internet access. You can use the site to  
determine whether or not your computer is on and it’s easy to remember the name in  
case you need it in the future:

http://www.ismycomputeron.com/

Let me know if anyone is having any technical difficulties or anything, I just released it today.