Just to add a few technical notes to Eli's post. Dedoose should work on the mac pretty well, especially if you ensure you have the newest flash player -
http://get.adobe.com/flashplayer/ that adobe just released that adds GPU acceleration for flash. Dedoose is web based, very easy to use and intuitive. Especially in comparison to the other QDA software on the market. It is a web based application and can be accessed from just about any computer connected to the internet. It uses multiple layers of encryption and security management as well as allowing for your own data storage if your paranoid about that. We just released version 1.0, and should have 1.1 out pretty soon which adds support for memo's / bookmarks and the training center or inter-rater reliability training, as well as a free version for testing that will allow a limited number of documents and such. All upgrades are free and seamless as there is no software to install. We will have a roadmap up on our site to show our detailed plans to include video & audio support along with powerful collaboration features.
~ JT