Ubiquitous Player is All-In-One multimedia player, web browser, image viewer, text editor and file manager. It doesn't need installation and can be used from your USB (100% portable).

It allows:
1) to listen to your mp3, flac, ape, aac, ogg files and CD music (including playback from folders)
2) to watch video files
3) to view images (with slideshow, gallery, fullscreen and stuff)
4) to edit your texts and use notes
5) to make simple HTML pages (with tags highlighting)
6) to rename/copy/move/navigate your files (file manager)
7) to use built-in web browser (with tabs)
8) to manage your Internet favorites
9) to take screenshots (of full screen or active window)
10) to extend your clipboard functionality
11) to use snipping tool
12) to use your gamepad as mouse
13) to use virtual keyboard
14) to use magnifying glass
15) to use calculator
16) to play some games
17) to do even more

Ubiquitous Player supports such types of files (and some more):
Audio files: mp3, ogg, flac, ape, aac, mp4, wma, wav, aif + module files: mod, xm, it, s3m, mtm
Video files: mpg, wmv, asf, avi (you'll maybe need some codecs installed)
Image files: jpg, png, gif, bmb, tiff, ico, wmf, emf
Text files: txt, rtf, html, mht