SD Card and USB, USB Display, Media Player and Documentation
Both the SD card slot, and the USB are located on the back of the PLED-W800. They can be used to load pictures and other files into the W800's on board memory. The USB also supports USB Display - which is basically hooking up a computer to the PLED-W800 using USB instead of computer (VGA) or HDMI.
The Viewsonic PLED-W800 has a tremendous range of capability for imported files, thanks to the USB and SD, and the Media player, plus several other capabilities if you have the wireless dongle as well. Some need to be downloaded, other features are built into the media player. There's downloadable vPresenter as an example. The main file support comes from the Picsel player which supports dozens of formats from pdfs to most versions of Microsoft Office products. All considered the W800 can support those mentioned, plus various music files, video files, and so on. AVI, MJPEG, DIVX, MP3, WAV, JPEG, JPG, GIF, MPEG, BMP, MOV, MP4, are a partial sample.
There's more than 10 pages of good documentation available about using the wireless, the players, etc., in the manual. Better info than most manuals seem to offer.
For that reason, you can click here to open the W800 user manual to browse. For player related, consider page 18 (playing videos), document viewing on page 23, USB Display (connecting computer to projector via USB) on page 25, Wifi Display on 26, and Media Streaming on page 29.
I did not get to explore a lot of the capabilities since I was not provided the wireless dongle with the W800.
One could do a long review just looking at the full range of capabilities of playing media with today's media player equipped projectors. Not going to try, but I thought including one page out of the manual might give you some
Note please that the less expensive W600 does not have these capabilities, including no SD card slot nor the USB.
Bottom line: The W800 is very capable in terms of "PC free" presenting, cable free presenting, and mobile device interfacing of all sorts. Note that the W600 is devoid of most of those same capabilities.