When you write notes with SimpleNote on your computer, do you use their program or can you use whatever text editor you want? SimpleNote sounds very cool, but I like writing stuff with vim when I'm on my computer, and I don't want to switch to some other application.
If you use Simplenote’s premium Dropbox sync feature, you can use any text editor. Otherwise your options are the Simplenote web app, Notational Velocity, DashNotes, or another app that syncs directly to Simplenote: http://simplenoteapp.com/downloads/