Host something on the internet from a box you physically own? Then maybe you'll be interested in this.
It's a website monitoring tool, although it doesn't really monitor websites. All you need is a valid URL or static IP address, and this will ping your box every 5 minutes or so.
If it looks like the ping isn't working (implying networking issues or that the server is down), you will be sent an email, and/or SMS, and/or tweet(why god why?).
So, if you're one of those people who likes hosting from your home computer, but suffer from brownouts or something silly like that, this utility can quickly inform you of unexpected downtime.
P.S. I dunno why I bought myself a byond subscription, but perhaps I'll actually play a bit on here in the future.