Weird Item in my Finder Menu Sidebar

I found this odd item that occasionally appears on my Mac (G4 with 10.5) and I don't know what it is.

I don't think it does anything and I'm not sure if the numbers stay consistent.

Can anyone tell me what it might be?

It's probably your printer. Mine does that when I have the printer turned on.
Right click on it and select Get Info. See if it gives you any details to determine if it is in fact your printer or some other wireless device.

I tried turning on my printer and using it, but the item doesn't reappear.

MasterDogma said:

I tried turning on my printer and using it, but the item doesn't reappear.

Click to expand...

Well, next time it shows up right-click and select Get Info. Report back here what you find.

The number is it's mac address.

Are you on a secure wireless network? It could be someone using your bandwith if not.

And that someone is showing himself in finder with his mac address? Please, people are not that stupid. Open up network utility and from there you can look up on other devices on your network. Clicking on netstat will tell you more then finder.

It appeared again today. I haven't plugged in, turned on/off, or removed any devices since my last post and the Get Info doesn't seem to be giving any information.

I'm connected via ethernet to a router. To my knowledge this never happened on my old G3 IMac.