Something so simple...
I purchased a Bell SIM card for a hand-me-down blackberry. It took 3 of the guys at the cell phone counter to first figure out which card I needed, then how to get it into the phone. I got the phone home, powered it up, and it said there was no SIM card. I showed my brother and in about 2 seconds he discovered that the SIM card had been inserted incorrectly. Turns out Larry, Curly and Mo put the SIM card in upside down. Yeah. Even though there is a little graphic showing which direction it's supposed to go.
THANKS GUYS!!
Sheesh.