Write now, tweet later.
Backdraft is an iPad app that enables you to write tweets in advance, and then release them while you are giving a presentation. You can engage the backchannel, while presenting from the front channel. Think of Backdraft like a remote control for Twitter – or a "tweemote."
Collect pre-authored tweets for your presentation around a hashtag or mention.
With each hashtag you can write as many tweets as needed. These tweets can contain URLs that will automatically be shortened or photos that will automatically be uploaded.
When you are ready to present, just tap the tweet and send. Backdraft will do everything else.