I used the same method to mail as molanic, because my package weighed less than 13 oz., too. Using paypal shipping is the only way I know of that allows you to pay for and print 1st class shipping labels online (and it includes tracking). I have some nice postal employees at my local PO., but the lines are dreadful. I much prefer to print my shipping label at home, then drop off the package in the drop box.
My package will be dropped off at the PO tomorrow on my way to work. Horntoad, I sent you the tracking number.
If anyone want any advice on the specific seeds I'm sending to them, just ask! Thanks to all of you for making this a fun swap