PyKeynoteTweet is a project mainly written in Python, it's free.
sends out tweets while you give your presentation with Keynote
pyKeynoteTweet.py by Heiko Behrens allows you to send out tweets while you give your presentation with Keynote. It does so by looking for the pattern
[twitter]your tweet[/twitter]in your presenter's notes. Each time a new slide with this pattern appears during presentation mode it sends out the payload using twurl.
Download and install twurl according to it's fabulous documentation.
Download and install appscript Python module.
Prepare your presentation.
Run pyKeynoteTweet.py and rock your audience!
Please note that this script relies on the default account of twurl. You can use this fact to test your tweets and/or tweet with different accounts. Also, open an issue if you missing a feature such as adding hash tags automatically.