With the growing lines at the PO I was thinking I was going to start sending stuff out using the APC Machine.  Can you use PBS Delivery Confirmation at the machine?  Do you scan the bar code somewhere?  I tried to use the machine last week and couldn't see any option for pre-printed DC, so I gave up and stood in the 15 minute line.

Yes, you can use PBS DC. There's a way to purchase "stamps" of any denomination from the APC, and you will need to figure out the correct amount yourself and use that option. The amount you pay is the media mail or first class postage plus 19 cents for the eDC. If you do it this way, it's the same as dropping the package in a blue box on the street. It gets scanned when it reaches a sorting center that has scanners. For me it depends which way the package is routed, and that is totally unpredictable (to me at least, the USPS probably has some reason for why each package goes the way it does). If my packages go to San Diego, they get scanned that same night. If they go to Bell, it's the next night.

I use the APC machine to weigh my packages .... just follow the prompts to "mail a Package" and it will get to a scale eventually .... then I weigh them all, sort them in piles (3 packages at 2.38, 2 packages at 2.77, etc) and then exit out of that screen and go back and buy stamps. It's easy!  (You can't continue with mailing the package because the APC doesn't have an option for Media Mail).

But, the DC won't be scanned right then when you mail it, you just have to add 19 cents for it to the postage. it usually gets scanned somewhere along the way, usually in a day or 2 for me.

I printed a sheet of postage prices so that I know how much to buy for each package weight ... I just keep it in my wallet.

What Sara said! 

But remember Rich, APC does not have a Media Mail option...but you can purchase APC postage stickers ahead of time and use as needed.  Remember to add .19 if you use DC.  Using this method, you will receive your credit when the package is scanned...which can be anywhere enroute or upon delivery, whichever comes first.  For me, Media Mail goes to a local sorting center so my packages are scanned within about 48 hours.  Other areas may have different procedures.