iTunes wallpaper "magically" appeared (+ no USB mouse)?

Strange sauce. I usually put my iMac to sleep at night (Snow Leopard still) instead of turning it off. Got up this morning and the iTunes wallaper was up, flashing little cards for different albums. Hit the spacebar and it went away.

► Weird thing is I wasn't using iTunes at all, this morning, last night, or for several days...

Also I have (and I know its blasphemy) a Microsoft USB mouse plugged in. Works better for some graphic programs like Pixelmator + no batteries required.

► But my USB mouse wasn't working. The light was still popping out of the bottom of my USB mouse.

Since OSX didn't detect a mouse, there was an icon on the Doc with a bowtie guy and Bluetooth was searching for my magic mouse. I put batteries in it and it worked immediately, so I just shut down my computer since I had to go to work.

►► Summary: Nothing changed since I used it last night. iMac was sleeping, but iTunes wallpaper was flashing album icons cards, turning occasionally, and my USB mouse was not working...bluetooth turned itself back on and was looking for a mouse.

Any idea?

120+ views and nobody huh? Well I got home and fired up my iMac and it came right on, mouse is working just fine. I did, however, find in the bluetooth settings the option to turn them on if no mouse was detected.

Best guess?

One of my cats probably jumped on the keyboard and turned iTunes on during the middle of the night and (somehow) managed to turn my USB mouse off.

1. Most of the 120 views were indexing bots for Google, but a fair number were probably people like myself who took a look, decided we weren't sure what the problem was and opted to think on it a bit/hope for more details.

2. I'm beginning to think we should make "do you have cats?" a standard question when strange problems appear. They certainly seem to love Mac keyboards, and have footing that activates strange things!