i dunno if w800 has flash lite (if you can open swf files then it does) but for using swf files and screensavers, wallpaper (basicaly handle them as images) on w810 a patch is required. if w800 has flashlite than it may be posible to patch w800 in order to use swf files as desktop or screensaver. If that doesn't wok you could flash w810 firmware to w800 and get flashlite that way.

As for flash enabled thems, all you have to do is upload the swf files to "flash" directory and modify the line <Desktop_style Type="File" Source="flash_file.swf"></Desktop_style> replacing flash_file.swf with the name of the swf files uploaded.