Fire up the grill at your home or at the park.
Have your guests come dressed up in costumes.
Go out to a nice restaurant with your friends and family.
Have each guest bring over a bottle of wine for a wine tasting party.
Setup a few stations with casino games and give an equal amount of chips to each guest at the begining of the night. Give out prizes to those with the most chips at the end of the night.
Have each guest bring over a dish to eat.
Gather a group of friends together and go to a paintball field.