Well, here's my .02 and I hope it doesn't seem biased since I am a Postal employee

I think a seminar like this is a great idea- here's why...
The Postal Service is/has been doing a lot of customer research to try and best meet their needs and do it in a cost effective manner. Before Christmas, they were test marketing the flat rate Priority box- much like the flat rate envelope. This is a decent size box and it ships for $7.70 no matter what the weight. Definately a good deal when shipping heavier items. There has been a lot of positive feedback concerning this and I think we will continue to see it and possibly other offerings like it in the future.
There are many shipping options and most people don't fully understand them all. On this board alone, I have seen confusion over what can be mailed using Media. There are smart ways to package things, and not so smart ways- unfortunately, I see far too many Not-so-smart things every day.

Also, there are regulations in place for everyone's safety that not everyone is aware of. I'm not sure what exactly they would talk about, but it will probably be informative and a great way to get any questions answered.
I have been toying with making a post here with tips for wrapping and addressing your packages to help them be delivered quickly and safe and sound. Right now I work in a processing plant that handles tons of packages every day. You wouldn't believe how some things come in.
Once there were swords- full size blades, SHARP metal with no covers that came in. They were only wrapped in brown paper- like a grocery bag. It seemed secure at first, but the mailer probably didn't realize that traveling in a truck would help the swords break through the string and paper eventually. They got to their destination, but it took a lot of special handling and it was fortunate that noone got injured.
Just today, I had a brown envelope full of Dvd's, an action figure and some movie cards that had burst open. It was only in a brown envelope- no bubble wrap or plastic bag. The right packaging would have made all the difference. That package had to be taken out of the mailstream and put aside to be resealed and fixed the best that it can be. That may add a day or two to the delivery time and hopefully nothing was lost out of it along the way. We work very hard to recover anything that may have fallen out and keep it all together, but it's impossible to be 100% all the time.
Oh, by the way, the stuff in this envelope could have been put into one of those $7.70 boxes- it would have been cheaper to mail and would have been safely and securely on it's way.
Sorry, didn't mean to turn this into a novel, but I wish people could see how involved the mailing process really is. You might gain a lot of helpful information at the seminar and the most you can lose is a little time if you feel you didn't get anything out of it.
Oh, and my NUMBER 1 tip for helping to get your packages to their destination quickly- ZIP CODE!!!!! Print the Zip Code CLEARLY and LARGE. DON'T put auction #s, phone #s or any other type of number under or near it!!! Have it be Highly visible and easy to read. Even if you print your labels online, you can still take a sharpie and write the Zip under the address.
Why will this help so much? Most packages go through a machine- it goes up a conveyor belt and the zip code is keyed in by the clerk. That tells the machine which container to drop it into. The containers are then loaded onto trucks and sent to their destinations. We usually key in roughly 700 to 800 packages each HALF hour on each line. They come up the belt very fast and if the zip code is hard to read or very small, it may be keyed wrong. Same problem if there is an auction or phone number underneath and it's mistaken for the zip. It can make a big difference. We do have quality controls and do checks along the way but it's impossible to catch everything with the shear volume of mail that is processed. Our percentages are actually quite good but we're always striving to make them better
