BlogCatalog recently opened BloggersUnite.org to help bloggers find events to participate in or to even host their own. These things, properly promoted, can be really popular and great for networking with other bloggers.
From the BlogCatalog team:
Supporting each other by doing good can help you make friends online or in your area, as we all work together to make the world a better place. Even better, once you become a member and write about any worthwhile events that you care about, your blog will automatically be promoted on Bloggers Unite.
Here are some that are live on BloggersUnite right now:
Getting other bloggers to rally behind an event, or simply setting one up from scratch can be a pain. Bloggers Unite is an effort to help you with the technical stuff along with giving you an instant stage upon which to gain a lot of supporters from the Blog Catalog community.
