If slide decks are part of your daily routine, you know what a hassle it can be to show them from a laptop.
You have to connect a projector, wait an eternity for the PC to boot, run PowerPoint, load your slide deck, switch the laptop's video output to projector mode, and so on and so on. You can blow 10-20 minutes just getting set up for your presentation, which is not what I would call a productive use of your time.
Like the iPad version, the new app combines software and service. Both are free, though you'll have to see if you can get by on the 100MB of storage afforded by the Starter account. If not, pro-level plans start at $49 annually.
After installing the app and signing up for a SlideShark account (something you can do right inside the app if you prefer), you simply upload your slide decks, then wait a few minutes while the service optimizes them for iDevice viewing. SlideShark supports both PPT and PPTX files.
Then you fire up the app and choose the presentations you want to download. I like that SlideShark stores the presentations on your iPhone (or iPad) so you can run them offline, no Internet connection required.
You can review your slides on your iPhone, zooming as necessary for better views of the content, but obviously the real draw is connecting to a TV or projector -- no laptop required. For that you'll need Apple's VGA Adapter, a $29 accessory.
As with the iPad app, there are a few limitations. SlideShark doesn't support hyperlinks, embedded videos, slide transitions, and other fancy effects. In other words, you're stuck with fairly static slides (which is not necessarily a bad thing). The app does promise to preserve all fonts, images, and colors, plus some animations.
In my brief, informal tests, SlideShark did a great job converting most of my presentations. Your mileage may vary, especially with odd-sized slides, so be sure to spot-check any important presentations before actually, you know, presenting them.
There are, of course, countless other apps that let you show slide decks on your iDevice. But SlideShark has the benefits of being free and easy to use. Definitely worth a try if you'd rather travel with a slim tablet than a bulky old laptop.