Some clever folks on Turk Forums (registration required), the leading forum for TracFone, Net10 and StraightTalk users have discovered an undocumented feature in the $49.99 LG 800g, TracFone and Net10's first touchscreen phone.
It's the Picsel Document Viewer and it lets you view PDFs, Text files and Microsoft Office Excel, PowerPoint and Microsoft Word files as well as Open Office/Libre Office ODF files.
The viewer works with the legacy Microsoft Word (.doc), Excel (.xls) and Powerpoint (.ppt) files. It does not work with the new Office 2007 and latter file formats (.docx, .xlsx and pptx) but new versions of office can save in the older format.
To use the viewer, first just copy the files you want to view into the memory card's MYSTUFF/DOCUMENTS folder using a data cable or card reader. Then tap the menu icon in the lower right corner of the screen, tap the MyStuff icon on the next screen and then tap Documents. You can zoom in and out in the viewer and switch between landscape and portrait mode. It's strickly a viewer, you can not create or edit files with it.
The document viewer is the sort of app that you usually only see on smartphones so having it on a $49.99 prepaid phone is a great perk.