I don't know about you, but when I get ideas they come in bunches. When I log into twitter I feel bad for those who subscribe to me as I will tweet my face off for 30 minutes and then disappear for days. Well I found a free tool that will help you with that, and spread your tweets out over time automatically.
All you do is set your time zone, pick what time you want tweets to go out, and then start writing tweets. At the scheduled times your scheduled tweets will be sent out. Best of all its free. If you want to have more than one twitter account it's $10 a month. You can add tweets to your Buffer from any page with one of the browser extensions (Chrome, Safari or Firefox), which makes it even simpler to put tweets in your Buffer.
It's not just twitter. You can tie in your Facebook (page or profile), and linked in. You can schedule 10 tweets at a time for one account (so you could have tweets, 10 facebook updates, I haven't really tested that yet).
For ease of use and Power I really like it. Check it out at bufferapp