HiCan a clock radio (or any handheld or car radio) pick up ATC? Just something I was wondering about.

Although FM radios are capable of receiving VHF frequencies, I believe the highest they can tune is 108.0 MHz, and think the ATC VHF frequency band is 118.0 to around 136.0, so I don't think you would be able to listen to ATC with an unmodified FM radio receiver.

No. You need a receiver that can tune VHF 118.000 MHz to 136.975 MHz in AM (Amplitude Modulation).Cheers,- jahman.