Do the conga

I recommend the Grove Park cafe in the Ally Pally park, run by an Italian man who will:

Lead an impromptu conga
Sing "Give me cornetto..." when handing over your ice-cream
Give you a bag of frozen peas if you bang your head
Dance with you and then suddenly swing you upside down
Go through an entire Stevie Wonder album trying to find the Happy Birthday song - insisting everyone wait for it whilst the candles are burning into the cake
Give out free lollipops

I think it helps if you are a child at a birthday party though.

No matter, he was fabulous and I want to keep him.