I’ve recently discovered two intriguing new ideas from the blogosphere: grid blogging and The Internet Topic Exchange.

Grid blogging is when many bloggers blog about a single, predetermined topic on the same day. The first grid blog happened yesterday. Dozens (or more) bloggers wrote about the topic brand. My friend Johanna Rothman wrote about it twice, once on her “Managing Product Development” blog, and again on her “Hiring Technical People” blog.

As the day of the first grid blog approached, a number of people wanted to know how they could quickly find all of the blogs that were participating in the grid. Hal Macomber suggested that every grid blogger add the specific label “[grid::brand]” to the titles of their entries. That way, interested readers could search the Internet for “[grid::brand]” to find all of entries for the “brand” grid blog.

One drawback of search engines: They don’t update their databases every day. If you had searched for “[grid::brand]” yesterday, you would have found very few of the grid blog entries. Some people wanted to know how they could find the “brand” blog entries early, before the search engines had updated.

That’s where the second intriguing idea comes in. The Internet Topic Exchange is a centralized web site that categorizes blog entries into “topics.” It includes a semi-organized directory of topics and a list of all topics. If you’re interested in photography, for example, you can look at the photography topic to learn who has been blogging about that. And if you have an RSS reader, you can subscribe to the topics that interest you, and be notified whenever someone blogs about them.

The grid bloggers created a category called gridbrand, and a number of gridders posted links to their blog entries. People who had subscribed to the topic were notified immediately that someone had written a new entry about branding.

The Internet Topic Exchange is, as far as I can tell, still in its infancy. The directory of topics seems incomplete. The list of all topics lists the topics in some arbitrary order (definitely not alphabetical). And some of the topics have puzzling names: coolest, for example. What with those underscores? Or amazonand_ebay. Why lump Amazon and eBay together?

If the topics in The Internet Topic Exchange were cleaned up and managed well, I think it would be a very handy tool for bloggers and blog readers.