Well, I finally made the leap up to the Parallax Propeller. The Propeller chip is fantastic step forward in microcontrollers. Its eight processors (cogs) can operate simultaneously, either independently or cooperatively, sharing common resources through a central hub. The eight 32-bit processors (COGs) allow real simultaneous multi-processing! The chip is the result of eight years of work and was designed at the transistor level. The Propeller chip is programmed in both a high-level language, called Spin™, and low-level (assembly) language. With the set of pre-built Parallax “objects” for video, mice, keyboards, RF, LCDs, stepper motors and sensors, a Propeller application is a matter of high-level integration. The Propeller Chip represents the first custom all-silicon product designed by Parallax.
To learn about the Propeller, I chose to buy the Propeller Education Kit - 40 pin DIP Version. This is a complete kit with everything you need to get started with the Propeller microcontroller. Parallax's website has educational labs that you can download the free. The Propeller Education Lessons and Labs utilize the parts in the kit, and new Labs will be released periodically. This kit features breadboard-friendly versions of the Propeller chip, EEPROM and other core components making it easy and inexpensive to learn about the Propeller. If you mess something up it doesn't cost much to replacce parts as needed.
I also bought the Propeller Manual. The Propeller Manual contains detailed Propeller chip architecture information, along with complete syntax and reference guides for both Spin and Propeller Assembly languages.
For spending more that $100, Parallax was offering a free gift of the Propeller Proto Board (Serial Version), so I recieved it too. There are some really fun and educational resources for the Proto Board avaliable on the Parallax Forums produced by user "Oldbitcollector." These resources include the Intro to the Propeller Proto Board and The Propeller Cookbook.
Learning all that the Propeller can do will be a slow process, but there is a lot of help avaliable on the Parallax Forums and at the Propeller Object Exchange. This exchange includes other users solutions to common programming problems which are shared freely on the web. I've already had several folks offer to help me learn or share their code with me. That's one of the reasons I enjoy this so much!
Note: Photos and much of the info above is courtesy of Parallax's excellent website.