For my husband's 40th birthday I planned a surprise Luau party.  I mailed out invitations that had a girl in a grass skirt on it and it read something like We are having a luau and to dress like a tourist and the date, time and address. I strung a big blue tarp (I had 4 tarps) across the yard for privacy from the street and attached fish nets and fish to it and I had our bar moved outside and decorated it with fishnets and flowers and star fish.  I had tiki torches all over the yard and had an inflatable kiddie pool with floating candles in it and had party lights strung up all over the yard. For the table center piece we made a paper mache pig head and put garland around the table.  We made shish kabobs and burgers and hot dogs, potato salad and baked beans.  I had a watermelon fruit basket made and it all looked great. For drinks I bought coconut cups with straws that had umbrellas on them and we had hurricane glasses (we used these for our fruity alcoholic drink)  I had a big plastic pond liner and filled it with ice and dumped cans of beer and soda and used colorful can holders.  When people showed up they all received a lei to wear around their necks. When my husband came home I put on Elvis' Blue Hawaii song so the guests knew he was there.  He was totally surprised. I played Jimmy Buffet, the Beach Boys and other beach party songs. It was an awesome time!  Everyone wants me to do a party every year now!