passport needed to leave?

Sooo.
In light of everything and after serious consideration, I am officially leaving the country and returing to Guatemala.
I hate to sound slightly ignorant about this, but do I need a passport to leave? I mean, I know that one is now required when leaving and RE-ENTERING the country, but seeing as I won't be doing that in quite a few years.....it is necessary for me to go renew my passport? (It expired about a month ago)
Also, my doubts about this were slightly quieted by another poster in another thread, but is there a chance I could get detained in the process of leaving? Any other thoughts on this? I just want to make sure. I would hate to put myself in a position where my chances of someday acquiring US Residency could be damaged, and what's more, have my luggage confiscated or something.
You guys never fail to come up with the most informative answers ever, so thanks in advance for any replies.

Yes, you do need a passport to leave the country. Either you drive to Guatemala, in which case you will have to go through Mexico i.e. enter another country, or fly there and your passport will be inspected by the TSA employees when flying out.

I don't know your situation but if you decide to leave, your chances of ever coming back legally will be very small. I don't know if you overstayed or EWI, but the best case scenario you are looking at is at least a 10 year ban. And from what I heard, after the 10 years it is not like they are just going to welcome you with open arms. 15 might a reasonable time, and 15 years from now, if you are still looking foreward to coming here then in my opinion the last 15 years were wasted. If I were to leave ( which I might do sooner than later) I would close the book on the US, hoping that my inability to ever come here again wouldn't interfere in any way with the life I started in another country,

I wouldn't incur a ban and my papers are already in transit through consular processing.
This a big decision, which has taken lots of planning and thinking, and it should be inferred that I have a carefully thought out plan. I don't think many of us leave this country without understanding completely what our chances of returning are.
Thank you for the reply, nonetheless.

u must not give up my friend, this is what they want for u not to succeed you are not the only one its hard yes, it is very tough to be here without any papers but u must not give up, i had your thoughts in my head also, i wanted to leave also even my father asked me if i want to go back and he will buy the ticket. i understand where you are coming from your just like me, im just like you , same situation, same way of thinking what u going through maybe hard but remember someone else it is more difficult for. u going back could be the biggest mistake of your life but this is your choice.

I would say to wait a little bit more before committing to your decision. If you do leave then I wish you the best ,and applaud you for having the guts to actually leave and pursue your life elsewhere.

We have all had these thoughts and for me they still exist ,but I try to put it off as much as I can.

Suerte

I'd suggest contacting the nearest Guatemalan consulate in person, e-mail, letter, phone call, etc.

The staff should have a good amount of knowledge on what you should do.

If the economic situation doesn't get better anytime soon I might follow suit.

After listening to the bad news that Nouriel Roubini (notable economist and a predictor of the recession) mentioned today I'm considering it.

what are the bad news ?

http://news.bbc.co.uk/2/hi/business/8298182.stm

No you won't get detained. Yes, you need a valid passport to leave.

If I were you I'd wait a big longer because there are rumors that an immigration bill will be introduced next Tuesday. I don't know how true this is, but maybe something you should consider.