These days, there's no need for a Court Jester - the Royals seem to make their own laughs.

Prince William recently demonstrated his lighter side when he adopted the Ali G pose while winking for the cameras, filming him during his gap year in Chile.

And he is not alone. Only this autumn, the Queen showed her sense of the ridiculous when it was revealed she had become hooked by Big Mouth Billy Bass, a battery-operated singing fish.

Not to be outdone by a million of her subjects, who each own one of the £25 wall-mounted fishes, Her Majesty keeps Billy Bass on her highly-polished piano at Balmoral.

As the mounted rubber fish moves its mouth and flaps its tail, the Queen is said to sing along with Don't Worry Be Happy and Take Me To The River.

She has also taken delivery of Rocky Lobster, a crooning crustacean, who has added Do Wah Diddy Diddy and Rock The Boat to the Royal repertoire.

Big Mouth Billy Bass even cracked a smile on the face of the Queen's hard-working, no-nonsense daughter, the Princess Royal.

Mimicry is another way to raise a Royal chuckle and it's not Rory Bremner who does the impressions - it's the Queen.

She is renowned in Royal circles as a talented mimic and has been known to turn her skill on the rich and famous.

It's a talent that she has passed on to the heir to the throne, the Prince of Wales, who started to develop his mimicry from an early age.

Charles, while a schoolboy at Gordonstoun in Scotland, recorded his impersonation of the distinctive 1960s' Scottish broadcaster Fyfe Robertson.

The teenage Prince, who while a teenager infamously slipped his leash to sip a naughty cherry brandy in a local pub, was recorded by his police bodyguard mimicking a woman complaining about Harold MacMillan's government.

In adulthood Charles became an honorary Goon, striking up life-long friendships with Spike Milligan, Harry Secombe - who was later knighted - Peter Sellers and Michael Bentine.

The Prince would entertain the Royals with his version of the programme's Ying Tong Song which he rehearsed to perfection.

He has said: "It has always been one of my profound regrets that I was not born 10 years earlier than 1948, since I would then have had the pure, unbounded joy of listening avidly to the Goons each week.

"Instead, I only discovered that the Goon-type humour appealed to me with an hysterical totality just as the shows were drawing to a close.

"Then I discovered the Ying Tong Song in record form and almost at once I knew it by heart.

"I plagued everybody with my dulcet tones and Solo For Raspberry Blower to such an extent that when my small brothers heard a recording of the Goons for the first time they thought it was their eldest brother."

Former Goon Secombe has praised the royal efforts. "Prince Charles is a great bloke. He could do the whole Goon show on his own - he knows all the voices."

In later years, the Prince declared himself a fan of Dame Edna Everage - the housewife superstar created by Australian Barry Humphries - and TV's The Baldy Man, played by comic Gregor Fisher, alias Rab C Nesbitt.

Another Scots comedian who is popular at Buckingham Palace is Billy Connolly with his bawdy brand of humour while BlackAdder, the television creation of Richard Curtis and Ben Elton, is a right Royal rib tickler.

Rowan Atkinson and Stephen Fry were enlisted by Prince William and Prince Harry to perform a surprise BlackAdder sketch for Charles at Highgrove, his Gloucestershire country home, as a 50th birthday celebration.

Princess Margaret, who was once close to late Goon Peter Sellers, is a practised mimic in the tradition of the house of Windsor.

The Queen's younger sister once starred with Sellers in a home movie, singing the gang show theme song I'm Riding Along On The Crest Of A Wave.

Even the Queen Mother at 100 years old still enjoys a good laugh at TV characters such as that eternal snob Hyacinth Bucket - pronounced bouquet' - who is played by one of her favourite actresses, Patricia Routledge, in Keeping Up Appearances.

Another enduring favourite at Clarence House is the recently knighted Sir Norman Wisdom whose slapstick humour harks back to perhaps a more innocent age. TV comedies 'Allo 'Allo, Dad's Army and The Two Ronnies were also required viewing in the Queen Mother's household.

But it has to be said that not all comedy shows have had the Royals rolling around with laughter.

Spitting Image, whose satirical and often grotesque latex puppets poked fun at the Establishment, went too far for many of the Royal Family who were frequently featured.

Most offended was Diana, Princess of Wales who told friends she thought it was "cruel". Diana preferred the humour of Absolutely Fabulous with Joanna Lumley and Jennifer Saunders.

The exception were the Duke and Duchess of York who were Spitting Image devotees. Intriguingly, Fergie once kept a framed picture of Diana's puppet on her office desk.

A youthful and exuberant Prince Edward enlisted the Royals in an apparent bid to get his own back on the viewing public who so loved Spitting Image, but the Royal It's A Knockout failed to live up to its name - we were not amused.