I have found Evernote to be a pretty nice note taking app, and it comes with a couple of widgets.
I personally prefer Ghost Commander for a file manager. Those that used Norton Commander or Midnight Commander will greatly appreciate the interface, or those that like FTP. It shows two views of the file system so you can copy files easily from one spot to another.
Springpad is also a good note taking app if you want sync between other devices and have web access, Evernote does this also. For a Dropbox type app there is also Spideroak
