I'm looking for a wiki-like program which has the following characteristics:

• Easy - I don't want to spend time on the program
• Just for me - not publically available on the web
• Persistent - I've been using sticky notes, but they are just not persistent enough - not versioned, and they really feel like they should be thrown out regularly
• Works everywhere - Windows at work, Mac and Linux at home
• Hierarchical - I want to link from "stuff to do" to "how to do task X"

Really, a wiki is ideal, except all of the wikis I know need a web server, and what I really want is more like a cross-platform Tomboy. Does such a thing exist, and I just don't know about it?

Update: Thanks to Emmanuel Touzery and Stewart Smith for quick answers - Emmanuel reccommended Instiki (which I believe Nat mentioned a few weeks ago too). 2 clicks, and I was away. Exactly what I was looking for. Bummer that it doesn't use the same wiki text as moinmoin, but you can't have everything ;)