Twitterbook

Twitterbook is a mashup that lets you use your Facebook status to update your Twitter account. Download Twitterbook v3 (4KB)

Connect with the developer on Twitter at: twitter.com/designmeme

LastFM Love Twitter Mashup

LastFM Love/Twitter Mashup will automatically generate a tweet from you that has the track’s artist and name, as well as a link to it for any track you love on Last.fm.

Twiike

Twitter your Nike+ runs. If you have your Nike trainers plugged into your iPod with Nike+ and want to share your runs with your Twitter Friends, you can with Twiike.

How to Sign Up:

1. Enter into your Nike+ username & password.
2. Enter your Twitter username & password
3. Twiike will automatically post any run you sync after entering your Twitter info.

iPhoneTwitters

iPhoneTwitters is a Twitter mashup which uses location data provided by iPhone Twitter clients and displays tweets on a Google Map.

TwitterFountain

TwitterFountain is a Twitter/flickr mashup that lets you see both the tweets and the images that share the same tag. You can take the resulting mashup display and embed it onto your website.

Twizon

Twizon is a mashup between Twitter and Amazon. The app lists all the tweets that reference Amazon deals so you can find out what’s popular.

Twistory

Twistory is a Twitter mashup that lets you easily subscribe to your backlog using your favorite desktop or web calendar tool. Twistory launched during Mobile WebCamp Hasselt and is currently being finetuned.

Custom Twitter Groups

Christoper S. Penn shows you how to make custom Twitter groups using Yahoo Pipes. Check out his blog post for the details.

Twitterlocal Meets Google Maps

Twitterlocal Meets Google Maps is a mashup app that lets you enter a City, State or a Zip and see those tweets displayed on a Google Map. Not much more information beyond that is provided on the site, but it works as advertised.

Slandr

Another way to get to Twitter on your mobile phone: m.slandr.net. Their tagline is "mobile.twittah!" Links give you access to replies, directs, search, users, public timeline, friends timeline (home), and even "geo," which seems to be taking advantage of the new Twitter API function that allows you to update your location.