I have a friend who is thinking about having them in the teeny little bowls about the size of a softball at her wedding upcoming in May. She is having something in the neighborhood of 175 guests - and there will be about 8 guests per table. She wants to have at least one fish per table. That comes out to 22 bettas - and I'm sure it would be more, maybe even 2 per table, because they'll be in such small containers.
She doesn't know the first thing about fish (she admitted this to me) and I'm sure hasn't even thought about what to do with them after the wedding. I've already warned my boyfriend that we may be dragging a buttload of beanie boxes with us to rescue these little guys and drag them all back home again.
I am personally pretty opposed to having these things on a table at a wedding, and there's just one main reason why. Think about wedding receptions, and then the dances. You've all been to the wedding dance where people get obliviously drunk and do incredibly stupid things. I'm sure that some poor betta would be subjected to a nice dose of beer or other form of alcohol, or some drunk guest would think it was funny to dump 2 of them together, etc. I'm just dreading this wedding all together.