WriteMonkey does look like just the ticket.
To get it to start up like you want, see if it takes command-line parameters and stick that in your startup script.
Q10 looks similar, but less features:http://baara.com/q10/
Come to think of it, if you're still using XP you could even go with a minimal Explorer replacement like LiteStep
, but that's probably more work than it's worth.
If you're using Windows 7, it's recommended to use the Omar installer
(LOSI doesn't like Win7...)
I found a few similar editors for Linux, all more or less based on WriteRoom
for Mac OSX:
Written in Java, so it runs on Windows natively and the Linux version interface is Desktop-Environment agnostic.
Has a 'no delete' mode as well.
Last updated May 2010.
Requires GTK, dunno why, there's almost no interface...
Not much feature-wise but soon will have plugin support.
Last updated March 2009.
Sports a TON of features, including 'flow mode', typewriter noises, scratchpad, and a Mindmapper flowchart thingy based on Flo
which looks quite useful.
Updated recently; as in Yesterday...
Windows portable version available with integrated libraries.