I absolutely add it to my task list, in one of these ways:
- WFR (waiting for response/reply (from)) {person} re {subject}
- FUO (follow up on) {subject}
Or, if I first have to do a task, then get a response, I surround the task in parentheses instead of crossing it out to indicate that I did it but I'm waiting for something else to happen (usually for someone to call back or something). For example, if my task is "call helloworlddd", and I do, but you're not home and I leave a voicemail, then
- call helloworlddd
becomes
- (call helloworlddd)
and when you finally call back I cross the task off.