Guests sign wine corks instead of a guest book. After the wedding you can put them on display in a vase, bowl, or even create a fun cork board with the signatures facing out. Or guests sign wine bottles to be opened on anniversaries
Ask the bartender to save all the wine corks from the wedding. Glue then together to make a letter for the mantle. That is freakin awesome! cute reminder of wedding reception (also save some bottles for other DIY projects?