Pippa Middleton drew cheeky admiration from around the world as she stunned onlookers in a sleek white dress at her sister's wedding.

Stepping out of a Rolls-Royce wearing a cowl-neck dress which showed off her slender figure, Miss Middleton soon became one of the most talked-about topics on social networking sites.

The 27-year-old maid of honour even risked upstaging her sister as she mesmerised millions of viewers by taking to the red carpet in an all-white dress with a plunging neckline.

Thousands of people on Twitter commented she looked "absolutely stunning", making her name one of the day's hot topics, while for others she was the "most beautiful person I've ever seen in my life".

Looking the picture of elegance, Miss Middleton led a troupe of young bridesmaids and page boys into the abbey, holding hands with three-year-olds Eliza Lopes and Grace van Cutsem, before returning outside to help Kate with her train.

Caroline Dennehy, of Hertfordshire, added: "For me, it's Pippa Middleton that has stolen the show today - she is Beautiful!"

Speculation also mounted over whether Prince William's brother, Harry, who walked alongside Miss Middleton as the pair left the abbey, would fulfil the traditional role of the best man by getting to know Miss Middleton better as the parties at Buckingham Palace get under way.

Former England cricket captain Michael Vaughan tweeted: "Tell you what!!! Pippa is fit..."

But it looks like Harry will be out of luck as Miss Middleton is reportedly dating cricketer Alex Loudon.