open usb text file w/o .txt extension

[fciron]

You can rename the files on your thumbdrive using the Terminal Activity.

If you are not familiar with the Linux command Line I would suggest checking the Linux Documentation Project for some introductory info or try typing "mv --help" at the command prompt. 

Aw, heck, step by step as close as I can remember

Open Terminal Activity (rectangle with a $ sign in it)'

Click with the mouse inside the window to get the proper focus.

Type 'cd /media'    -- change directory to /media

Type 'ls'                -- List files and folders in the current directory, you should  see the name of your thumb drive or sd card in blue

Type 'cd yourDrive'     --change directory to your card

Type 'ls'      -- so you can see what you're working with, bash is case sensitive

Type 'mv oldname newname.txt'    --This will change your file to a .txt file, you can use the same name again if you wish