The first part of our twitter integration can be viewed here:
http://urlzen.com/twitter/[username]

(replace [username] with your twitter user).

Next we will make it easy to post to twitter from the bookmarklet.

Creating logins is a frequently requested feature, but it poses some challenges to a consistent user experience.

This would be similar to a twitthat.com - a collection of links that are stored locally, but also pushes the 140-character link + message to twitter.com. This would allow people to use URLzen even when twitter is down.

It can definitely make the site look bad.

It should be possible to have an auto tally of how many clicks you have generated over the whole time, and even some more data such as average number of clicks per tweet and maybe monthly averages... tweet people seemed to like data... and make it possible to tweet these stats

The "leaderboard" will show the top users, top links, top domains (linked to), top domains (clicked from).

make an api so i can use it with my site.

Pretty cut and dry. Kill the competition with stats AND aesthetic value.

since firefox toolbars seem to be the way to go, maybe a nice simple add-on that sits in the bottom status bar