It all depens on the station. XM will have a 15 second blurb about upcoming programming or how to request a song on most music stations. Other stations, like 165, the "ask" channel plays Paul Finebaum, a southeast sports-radio guy from 5-6 every afternoon. It's the exact same feed you get on AM750 in Birmingham, therefore you have commercials for local banks and mortgage companies and such.
I've also noticed a lot of commercials on any of the news or sports stations.
If you read the specs of the ipod, it says max pressure altitude is 10,000 ft.
The ipod is a hard-disk and the head floats (or flies as it were) a few microns above the spinning disk on a ribbon of air. When the air isn't dense enough, the head crashes into the disk, permanently ruining it. I didn't realize this until I'd killed the 2nd one... They seemed to work pretty well until you go above about 12000 msl, then they start to have problems like randomly soft resetting. At 180, I ended up getting permanent disk error icons. Also, the white top and metal bottom of the ipod seem to be very permanently attached, but once I took each one up that high it was like it popped open, you could almost peel the 2 halves apart... I didn't so applecare would still replace it. The ipod stays plugged into my Alpine car deck or on my arm at the gym nowadays.