The second-most surprising thing about the Marc Jacobs show during February’s New York Fashion Week was the unexpected appearance of the band Sonic Youth on the catwalk. As Kim Gordon, the petite, blond lead singer danced and thrashed about in place, one by one the models rotated through the darkened space, most of them dangling bowling-bag-size handbags at their sides.

But the most surprising thing involved one of those bags. Days after the show, the blogosphere was busily buzzing about it: The large, ostrich leather tote with sunray designs spreading across one side was called “BB”—and it turned out that the name came from Jacobs’ favorite blog, BryanBoy, a deliciously funny read obsessed with all things fashion, especially the blogger’s favorite designer, Marc Jacobs. The bag will retail this September for $1,295 in leather and $4,800 for the ostrich version.

“Love your passion for fashion—after all, where would designers be without enthusiasm like yours?” Jacobs is quoted on the 19-year-old Manila-based blogger’s homepage.

As a powerhouse designer and one of the key figures on our Brilliant List, Jacobs, who is notorious for running late (his shows rarely start on time), would seem to have little time to read blogs. But as the internet has taken on a greater role in fashion, from live video of the runways to up-to-the-minute perspective and commentary on the latest trends, it has become an essential source for designers. Besides BryanBoy, Jacobs also makes a point of reading the more serious On the Runway, the fashion industry blog from New York Times writer Cathy Horyn.

Jacobs isn’t alone in visiting the blogosphere with some regularity. In all areas of business, everyone from newcomers to captains of industry are finding it essential to make a little time for the internet. Those on our Brilliant List tap blogs to keep up with trade news, spot new talent, and find inspiration.

Paul Buchheit, the former Google software engineer who coined the company’s motto “Don’t Be Evil” and who developed both Gmail and the first AdSense prototypes, is fairly consumed by his most recent online venture, FriendFeed, a website that aggregates online profiles from various sources. Buchheit devotes most of his blog consumption through FriendFeed to read his friends’ latest blog entries in one spot.

But he also reads the blogs of other tech pioneers, including essayist Paul Graham, the developer of Viaweb, one of the first Web-based applications, whose eponymous blog is a how-to for tech startups and observations on tech culture; Netscape co-founder Marc Andreessen, who also writes regularly about investment and technology on Blog.PMarca; and New York-based venture capitalist Fred Wilson, a financier of del.icio.us and Etsy, who expounds on VC life in New York on AVC. For fun, Buchheit checks out the Dilbert blog.