@CoTweet
Giving out free invites for anyone who signs up for the beta version today. Excited to try this out for the @miis account!

@operationsmile
Non-profit running the campaign #140smiles as a case study for fundraising using Twitter. Check out 140smiles.com. Tweet that you are involved in the campaign and encourage your followers to become involved.

@Peoplebrowsr
Web-based Twitter client designed for community and brand managers and Twitter power users. The fundamental difference between PeopleBrowsr and other Twitter clients is that what you see on the screen is only the tip of the iceberg. You can search only people you are following, or only DMs, or only tweets from your followers.

@hootsuite
Web-based tabbed Twitter client that allows you to create groups. Supports RSS integration, builtin URL shortening, and rich stats.

@jobaba
On demand local business directory accessible via tweeting.

@tweetfunnel
A web-based app that lets multiple people (contributors & publishers) post from a single Twitter account.