Free Daily App from the Amazon Appstore
I took for granted that it was common knowledge that Amazon.com gives away a free, paid app everyday. I was talking to a group of Android users at my office who were absolutely delighted to find out about this. After all, different from Apple users, us Android folk are famously cheap.
So, if you didn't already know, you can get a different paid app everyday for free from Amazon. In my experience these are generally games, but I have found some great productivity and business apps there including Tasks N Todos, Documents To Go, and Splashtop.
Just navigate to Amazon.com on your phone and click on the link for Mobile Apps. Download and install the Appstore app on your phone (follow the directions). You will need to change something in your settings to allow the installation of un-verified apps. Once installed you can just browse the Amazon Appstore the same way you do the Android Market (Google Play).