Nicole's guides: Best Apps for Academics: Presenting

Give and view presentations

Keynote
Simplified version of Keynote for Mac. Make slides and display them with a VGA adaptor from your iPad to projector. Includes several themes, ability to view your presenter notes on the iPad, and swiping to advance slides. iPad only.
Slideshark
Upload a Powerpoint file to Slideshark, download it to your iPad for viewing and presenting, share with others and track the results.
Haiku Deck
This app makes it easy to design beautiful, simple presentations. It links to images with Creative Commons licenses allowing use in your decks. Beautiful, simple, wonderful! Free. For iPad.

Worth a look

Other presentation apps: Prezi for iPad, Explain Everything, Voice Thread, Photo Slideshow Director HD, 2Screens Presentation Expert
Presentation timer: Presentation Clock

Apple TV in the Classroom

Apple TV makes it easy to mirror the iPad screens of both instructors and students using their AirPlay technology. Connect this $99 box to your projector or large screen display, and you'll be able to easily show student work and classroom presentations. This makes everyone wireless so the instructor can move around the room.

Apple TV

Apple TV also includes YouTube, Flickr, Vimeo, and iTunes U, making it easy to project from those sources. You can also take photos and show them via Photostream (Apple’s service for instantly syncing photos on all your devices), with almost live updating as the photos are taken. This is great for classroom projects involving photos.

See: Why Apple TV & iPad Beats Interactive Whiteboard... Every TIme