FI and I aren't exactly having a sports themed wedding, however we are giving out rally towels at the reception.
I'm a huuuuuuge Phillies fan. I can't even begin to count the number of rally towels I've collected from their games over the past few seasons. Anyway, I decided I wanted everyone to wave rally towels when we were introduced at the reception. It's not quite the same as 45k+ at a Phillies game, but I think it will look pretty cool.
Anyway, we order them through rallytowels.com and they were delivered today!
Here's a crappy cell-phone picture of them.