The Sony Handycam DCR-SX40 is a flash-memory-based standard-definition megazoom camcorder. It features the same lens, sensor, and video processing as Sony's hard-drive-based Handycam DCR-SR47, which CNET has reviewed.
The SX40 has 4GB of internal flash memory for storage as well as a Memory Stick Pro Duo slot and allows users to record video to either. Compared to hard-drive-based models, the use of flash memory allows the camcorder to be extremely compact, more energy efficient, and less prone to failure caused by bumps or drops.
If you're interested in having more fixed internal storage, Sony also offers the SX41 and the SX60 with 8GB and 16GB of memory, respectively. The features of the models are otherwise identical to the SX40.