How was City Park? I'm in the NOLA-area and have often toyed with the idea of getting married there (I'm really cheap and simply CAN'T trim down my guest list)
So, I guess this isn't really decorations, but fireworks are always fun. Late June/early July is prime time to find them everywhere (so long as they're legal where you are) and can make for a cheap, flashy show.
Come on people, I know you're out there! Covington/Mandeville/Ponchatoula area knitters and crocheters interested in starting some sort of knitting group, PLEASE REPLY! I'm tired of knitting alone!