I was using my Roland Cube 30X today, playing guitar along with a song i was playing with my Zune (connected to the aux in, which is designed for that sort of thing). It was on Power Squeezer (2-watt mode) and medium volume.

In the middle of the song (not when i plugged in or adjusted anything), the amp made a sort of loud popping noise. My first reaction was "crap i blew my speaker" but it worked perfectly fine after that and everything still does. To the best of my knowledge, there's nothing wrong with it right now - but I'd like to know what could have caused that noise and how to prevent it.

Ibanez S520EX ~ Roland Cube 30X ~ Dunlop Tortex 1.0mm
My amp makes a popping sound whenever my freezer starts up, maybe it's an electrical thing.
Yeah, as pwrmax said it could be electrical interference. Have you got anything else plugged into the same socket as the amp?
My amp and freezer aren't in the same socket, but they're close by so I guess that's the same.
No, there was nothing else there... and nothing else on in my room except for one light.

Should I assume it's nothing to be concerned about?
Ibanez S520EX ~ Roland Cube 30X ~ Dunlop Tortex 1.0mm