Go on a boat ride
Do a once in a life time thing (something you'll never forget) think big and go wild!
Have a vintage tea party
Hire a look-alike celebrity for the day
Host a barn dance. They're so much fun and will have everyone up dancing and laughing their heads off.
Put up a 60's themed party
Check out the world of the odd and bizarre at Ripleys Believe it or Not!
Go on a Superbreak. You can choose an attraction to go to and get a lovely nights accommodation to go with it
Have a disco or a live band
Put up photographs of the person whos birthday it is around the room