The April 29 wedding of Britain's Prince William and Kate Middleton is more than an international spectacle, it's a chance for marketing pros worldwide to get creative. While the royal family has forbidden certain types of commemorative merchandise — tea towels and T-shirts are not deemed "in good taste" — that hasn't stopped established companies and entrepreneurs from trying to use the wedding to sell their wares. (Watch a CBS report about Royal wedding memorabilia.) Here are five of the worst offenders:

Rogaine fit for a prince
The hairline-restoration empire says it's been "watching Prince William's growing bald spot closely for years," and the company is offering assistance in the form of unscented hair-loss foam and a sponsorship deal. "William would be the perfect spokesman for Rogaine," a company rep said, noting that if the prince starts the treatment soon, "he won't have to worry about the hair that's not there" when he reaches the altar. Right, says Susie Anderson in LimeLife. "Something tells me Prince William will be turning this opportunity down." Rogaine is being "a bit cheeky," say the editors at Heatworld, "but you never know." A man's biggest fear is baldness, and William "just might go for it."

William-and-Kate courtship tours
London-based tour operator Celebrity Planet has introduced a $25 royal engagement walking tour including such highlights as: The office where Kate's great-grandfather practiced law (and started the family fortune); the shop where Prince Charles bought Princess Diana's engagement ring (now worn by Kate); the church where they'll be married; and the nightclub where Prince William jumped on a table and yelled "I'm free!" after breaking up with Kate in 2007. I had low expectations, says Sarah Oliver in the Mail on Sunday, but it actually "proved to be a fascinating, funny, and not remotely forelock-tugging tour of Royal Wedding hot spots."

"Royal Wedding" Lego
Apparently because you're never too young to start "pushing little Wills and Kate up the imaginary aisle," says MSN's CelebrityFIX blog, British toy store Early Learning Centre will start selling Lego-inspired "HappyLand Royal Wedding" toy sets in February. The set includes a miniature William and Kate in a gold-trimmed horse-drawn carriage, a royal foot soldier and calvary guard, and the Queen, Prince Philip, and their favorite Corgi. "It's just not right without a little Prince Harry to complete the set!" gripes CelebrityFIX.

Royal couple zombie T-shirts
Buckingham Palace's refusal to approve official souvenir T-shirts didn't discourage Paul Entwhistle, owner of the east London print shop Stick 'Em Up. For a tee representing the prince and his fiancée as zombies, Entwhistle "bastardized an original commemorative Charles and Di image," he says, "because one royal wedding is pretty much like any other."

English Princess boot camp
Although American Jerramy Fine launched her "Princess Prep" summer camp right before the royal wedding engagement was announced, the news spurred so much interest that nearly all spots in the summer 2011 session are filled. At the $4,000, week-long camp in London, American girls ages 8 to 11 will visit royal sites, learn royal etiquette, study real princesses and their charitable activities, and eat specially prepared meals served by a butler. Kate Middleton will not attend.