The Arduino Uno is the all-new replacement for the favourite and popular Arduino Duemilanove. Now shipping R3!
The Freeduino is based on the open source project version of the Arduino Diecimila. We've adapted the design for more convenience as a semi-kit!
SparkFun's minimal design approach to Arduino. This is a 3.3V Arduino running the 8MHz bootloader (select 'Arduino Duemilanove w/ 328' within the Arduino software).