Pingchat message. A competitor of the RIM's bbm. It has all the capabilities of blackberry messaging; message confirmation, group chat, media sending, etc;. It's multi-platform, it can be used on iPhones, Blackberries, and Android phones.
Kat: I pcm'd you yesterday with a picture of the beach! Why didn't you respond!
Ian: I never got a picture of the beach!
Kat: BS! I got a check next to the message which means you opened it!