I've been working on a RIA for some time. I've essentially built medium-fidelity wireframes, then put them together in InDesign with callouts and some basic information. I have to say I'm pretty unhappy with how they look and inform. I think the problem is I'm not happy with how they lay out, and I'm not sure I'm giving the right level of information.
Right now the pages are landscape, legal sized. The way I have them laid out, it just doesn't flow very well, but the screens need to be big enough to see.