Mike at Techcrunch has been looking at the classified ad space - picking out BlockRocker, rbloc and theadcloud as the most exciting additions. But as far as I'm concerned, theadcloud is the only really exciting service here. So what does theadcloud do? Very little, in fact - but it has the same brand of extreme openness that made del.icio.us such a success. Theadcloud is all tags, all the time - it lets you create a classified listing with a title and short explanation and then tag it so others can find it. There are feeds for tags and individual cities - I love the openess here.
One thing I would like to say: it seems to me that blogs are increasingly becoming the submit form for the web. As I've said before, an aggregator that collects structured reviews from around the blogosphere (ala iNods) will beat a centralised silo (ala Yelp and Riffs) in the long run. Does this apply to classifieds, too? I'm absolutely sure that it does - instead of submitting my classified ad manually to lots of different sites, I want to use my blogging tool as the submit form and let the aggregators collect, filter and present this information to potential buyers. I feel the same way about calendar events.