Yesterday, Luke Wroblewski – Chief design architect at Yahoo! – wrote a blog post singing the praises of audiosharing site Huffduffer. But it wasn’t Huffduffer’s service that got Luke W animated, so much as their sign-up page.

While most sites use a standard form with text-boxes and radio buttons for new sign-ups, Huffduffer presents its questions as a ‘Mad Lib’ style statement…

“I would like to use Huffduffer. I want my username to be _____________ and I want my password to be _____________. My email address is _________. By the way, my name is ______________ and my website is ___________.”

…which is kinda neat.

But Luke, being a ‘chief design architect’ (one of the world’s more tautological job titles), wanted to find out more. Specifically, he wanted to know if this style of form actually encourages more people to sign up than the usual Name: ___________ / Email address: __________ format. So he persuaded Ron Kurti at Vast.com to do some A/B testing and, whaddya know?, it turns out the conversational fill-in-the-blanks form increased conversion by 25-40%.

Given those impressive numbers it’s a cast iron certainty that in the next few months dozens of sites, starting probably with Yahoo!, will consider upgrading their sign-up pages to this new, friendlier format. The trick, of course, will be to get the wording just right – to customize each sign-up page for the site’s particular audience.

…which has given me an idea for a ‘fun’ weekend contest! Hurrah!

Read on at TechCrunch…