No idea why Twitter has not yet allow users to schedule the pre-written, post-dated tweets. For example, it would be a excellent service and can boost the productivity when you want to tweet hourly/daily/monthly announcements, create an appointment or milestone reminders, running time based contests, or notify subscribers about upcoming podcast or video episodes. Here is another roundup of twitter web applications to let you schedule when the tweets to be released in advance.

1. Twuffer, allows the Twitter user to compose a list of future tweets, and schedule their release.

2. FutureTweets is a free service that was developed to let you schedule your Twitter messages. Send it at a specific time in the future or send a reoccuring Tweet daily, weekly, monthly or even yearly.


3. TwitRobot, able to schedule your Twitter messages such as post recurring tweets, send future tweets, and send auto tweets according to category of your are interesting.

4. TwitResponse allows you to set unlimited amount of tweets and deliver to your Twitter page when you want.

5. TweetLater, a simple twitter tool allows you schedule tweets that will be sent out in the future. After the free trial has expired, it costs you $29.97 per month for use the professional service.

6. TwitMessenger, a new Twitter application allows you to schedule your tweets for future and publishes the scheduled tweets automatically.