A Royal Wedding is always likely to generate a large quantity of memorabilia, including a number of genuinely valuable items and a vast amount of mass-produced stuff which isn't likely to maintain any kind of value at all.

It seems unlikely that anyone could have predicted in advance of Prince William and Kate Middleton's nuptuals that the most talked about item would be the hat of one of the Royals not involved in proceedings. Well, unless they'd seen it of course.

Princess Beatrice's hat, designed by Philip Treacy, provoked some approval, rather more disapproval, and a great deal of laughter. A Facebook page has been set up in its honour which has gathered quite a following.

The hat's fans regard it as a Lady Gaga standard fashion-statement. Others observers have compared it to an alien life form and even a cat toy. It makes Magneto's helmet from X-Men look understated and could not possibly have been missed by anyone who saw the wedding.

So it's exciting to hear that Beatrice's hat is to be sold to a member of the public via eBay. (Usually we caution against using eBay as many items on offer are forgeries, but online fraud is probably not a game worth playing for the Royal family.)

Beatrice's mother Sarah Ferguson announced the sale on Oprah Winfrey. The hat may well prove to have excellent investment value as it is a unique and universally remembered piece from an event which will be long remembered. Watch this space for more news of this opportunity.