PROLIX  I used the earlier versions of Scribblet every now and again but didn't find it quite right for my purposes. This latest update (1.5) though has seen the multiple notes feature added and that's made a world of difference to how useful I find the application. I've now imported all of my old to-do text files which were cluttering up my desktop and can view and edit them all from within Scribblet, which sits quietly in the menu bar waiting for my call. Scribblet has gone from a useable luxury to a fully functional everyday application, I've even put it in my startup list!  
(Version 1.5)