I'm not an IA or designer by trade at all (Degree in Finance, work in Marketing), and I found that Keynote Kung Fu was incredibly accessible by almost anyone (myself included). I had poked around in OmniGraffle before, but KNKF was just so much easier to use, especially for whipping up quick visual examples of things I want to show.
True that the final product is more styled, but that's when you have to work closely with the designer to make sure they understand you're not implying that's what the final visual style needs to look like.
I've also used KNKF for doing mockups for usability testing, which works very well.
As a set of templates and design elements, Kung Fu is really awesome. Definitely money well spent and the buttons/UI elements more or less cover everything I've needed to do.
To me, the question comes down to what software do you prefer to use for protoyping: Keynote, Balsamiq, Omnigraffle?
Keynote seems to have the best alignment, auto-positioning, etc and a really easy to use UI. The only downside (imo) is that Keynote only allows you to edit in 1024x768 or some similar canvas size, whereas Balsamiq lets you go as large as needed.
Actually you can specify any pixel width or height. I'm not at my computer so can't give instructions on where to find it, but I know it's a little non-intuitive where it is. Just google it, but just wanted to let you know this is indeed possible.
Not tried that, but I got the Keynotopia bundle from AppSumo when the offer was on, and very happy with that. looks very similar to this, not sure which is cheaper/more complete.
Found it to be pretty good when looking to go a level up in fidelity from pencil and paper. The developers on tunedinapp.com seemed to like the results as it leaves a bit less to interpretation.
The built-in components are great if you're using mainly the standard iPhone look. My only drawback would be the lack of a 'master' slide with the iPhone in the background, but it's easy enough to put together.
Certainly worth a few bucks to see if you and your team like it.
I have never used it. It looks nice, the only thing against it I can come up with is that it doesn't look like prototypes but more like a finished product, so it might not be as suitable for early tests.
As someone who's been doing mockups in Pages/Keynote for a while, I found it to be a great resource of nice looking widgets and templates and well worth the $.
True that the final product is more styled, but that's when you have to work closely with the designer to make sure they understand you're not implying that's what the final visual style needs to look like.
I've also used KNKF for doing mockups for usability testing, which works very well.