This site provides a simple bookmarking service. We follow your twitter feed, and whenever one of your tweets contains URLs, we add them to your delicious.com bookmarks. Optionally, bookmark URLs in @replies to you. We'll even add a delicious tag identifying the sender if you like.
A few bit.ly users who also heavily use Delicious and Twitter have asked for an easier way to sync all these services. We recently came up with a pretty good way to automate this sync process using Twitterfeed.
Publish full articles without needing a blog or site. There's no setup or login. Just write your text and Write4net will publish it using your Twitter account.