In my mind the ideal app or solution is a single file or cloud app where I can organize personal notes on projects, configurations, insights, ideas, etc.. as well as noting major activities or occurrences of the day. My original journals saved me on a number of occasions. Unfortunately my tenacity for keeping one has suffered from a fruitless search for a suitable solution. Currently I’m experimenting with Evernote [http://evernote.com/] and Tiddlywiki [http://.tiddlywiki.com/]. They approach the problem from two different angles.
What do you use?