Over the weekend some friends and I went to South Mountains State Park. A beautiful place, back country camping next to the Jacob's Fork River, mountain biking trails, hiking up to the 80 foot High Shoals Falls water fall and back down along the river path. But one day our group split up into mountain bikers and hikers. With the understanding that we'd all meet again at 1pm, I grabbed my trusty new Motorola i880 cell phone to carry with me so I could keep track of the time. Sadly, I later discovered that the clock on the phone would not work unless the phone had a signal! So because we were in the middle of the mountains and I couldn't make a phone call, I also couldn't tell what time it was. Abso. Lutely. Ridiculous.
Any cell phone should always show the time on the "start" screen, whether connected or not. The same thing is true for all other core GUI elements like signal strength, messages waiting, menu choices, etc.