The PSP interacts with the outside world in five different ways. The most common method is via a Universal Media Disk (UMD), which looks much like a mini-cd in a shell (figure 5 & figure 6). This small encased CD holds 1.8GB of data, which is more than enough for a movie, game, or lots of music. Unfortunately, the UMD is a proprietary format that only applies to Sony devices and that means you will have a difficult time trying to put data on a UMD! In addition, it appears as if Sony will try to market UMD movies in the US for about $20. I may be wrong, but buying a movie just to play on the PSP does not make much sense. In all honesty, if you want to view movies on the go, I suggest you purchase a $150 portable DVD player.
Figure 5: UMD/CD/Floppy Comparison Shot
Figure 6: UMD Front and Back
The second method of data transfer is the Memory Duo Stick that is used to store game data files and more. While the size of the sticks are financially limited to about 1GB, that is more than enough room to hold an MPEG4 movie, your saved game files, and a few MP3s.
The third method for connecting the PSP to the outside world is via the USB cable that you can plug into your computer. With this cable you can access the Duo stick from your computer and upload/download files. While it is possible to use USB 1x , I recommend a USB 2.0 for faster transfers.
Next, you have the built in wireless connection. With selectable infrastructure and ad-hoc mode, you can either create your own mini-network or connect to an existing WLAN to play multiplayer games and get your PSP updates. This can be complicated by encryption requirements, but it is an excellent way to play multiplayer games.
Finally, and most oddly, the PSP sports an IR port that currently serves no function. According to online posts, the PSP might be able to be operated via an IR remote, and maybe even be able to control a TV or two. I suppose we will have to wait to see how this plays out!