Question
Having both plants, I now know the difference between daturas and brugmansias. I see so many people selling seeds from brugmansias. This may be a stupid question,but I never see a seed pod from my brugmansia. Where do they get the seeds? I have looked at the fallen blooms and don't see where the seeds could come from.  Thanks Ester

Answer
Hi Ester,
Your question is not stupid.  First of all, is your brug inside or outdoors?  If it is inside, it is not getting pollinated.  The primary pollinator for brugmansias is the hummingbird moth, also known as a sphynx moth or hawk moth.  The caterpillars that grow into these large moths is the dreaded tomato and tobacco hornworms that devastate tomato and other solanaceous plants (plants related to tomatoes, peppers, potatoes, petunias, tobaccos, eggplants).  Some brugs are infertile and cannot set seed due to intensive hybridization.  You can pollinate the plants yourself by transferring pollen from one bloom to another with an artist's paint brush.  Here is a link from the American Brugmansia and Datura Society which shows pictures of hand pollination of brugs.  
http://www.abads.net/hybridizing-basics/brugmansia_hybridizing_basics.htm
If the brug is pollenated, the flower drops off and the ovary is left behind and resembles a green nodule.  It will eventually elongate and take on the look of chile peppers, green beans or eggs.  The link I gave you above also shows seeds and seed pods.  
I hope this helps.
Tom