I wanted to be able to trim trailing whitespace on my file by opening the Command Palette and just typing it in. I was about to write my own plugin, when I noticed that the "trim_trailing_white_space_on_save" option was implemented in the Default plugin -- so I just modified that! I've put together a patch file which you can download at http://www.davidbaumgold.com/files/trim-trailing-whitespace.patch (or view at http://paste.pocoo.org/show/580870/).
The patch adds a text command to run "Trim Trailing Whitespace" from the command palette, and it operates either on the whole file, or on just the part that you have selected.
Servicio de atención al cliente por UserEcho