Well spilting hairs here but I dont work for SWA but do non-rev on them. Most folks consider ZED fairs and the like to be non-rev.

I poke my head in and say hi, mostly just to BS with the crew. I always like meeting new faces at my airline anyway. If they seem busy, of course I won't bug them.

If it's not my airline, I'll always check in up front while in uniform, even if it's a deadheading situation with a real ticket. I'd rather risk an eye roll from a Captain that doesn't care than have some guy that does care wonder who the hell I am in the back of his airplane.

Like I said in post #2; 20 different responses with 20 different opinions.

Most will be hard pressed to convince someone else that their method is incorrect

Juice you are correct and I don't think we can say that anyone answer is better than another. Do what you feel is appropriate for the situation.

Personally, I try to say hi whether I'm jumpseating, non-reving or positive space. Not always to the flight crew, sometimes its just the lead FA or the FA closest to my seat. I think its just a professional courtesy to say hey I'm here and don't be afraid to ask for help if needed. I see all of us in a limited group that knows a heck of alot more than even the most experienced traveler and if the need arises that another crew memeber or just an "able bodied person" help out I'd like them to know I'm there. Heck, most of the time the FAs are just greatfull they have someone to talk to about how crappy the day has gone or that some little brat in 3C spilled Coke all over the person next to them.