I just came across a couple useful websites for learning about apps that might interest you. The App Podcast offers nearly daily video demos of apps, and sometimes as many as four or five a day. You can watch the demos online or subscribe to the podcast via iTunes and watch them on your iPhone or iPod touch. Developers pay to have their apps reviewed, so it's not a typical review site. But it's hard to beat a video demo for getting a quick idea regarding whether you'll like the app.
Appolicious is also a great site for reviews, and it, too, has a twist: it's the first to combine social networking, ratings and reviews, articles, advanced content aggregation, and search. The social networking component lets you get app recommendations from friends and from other people who share your likes and dislikes. And the Appolicious editorial team also makes recommendations, telling you which apps to download and which to avoid.