Whenever you go out, is your briefcase bulging with notes? Or you jam a fistful of PostIts into your pocket and hope for the best? It'd be nice if you could bring all your stuff with you without having to bring the whole office along, or risk a serious paper cut.
Picowiki is a hosted wiki designed specifically to work well with your iPhone, Blackberry, or PDA. Sure, you can cram it full of stuff back in the office, but it features an easy-to-use interface and its own "markdown" language (get it? markdown, not markup) for formatting text. Instead of having to use regular HTML markup to create a heading, for example, you don't have to wrap your text in "<H1>" and "</H1>" tags—you just run a row of equal signs (=====) under it, and as if by magic, it's rendered as an HTML heading. There's also a GUI toolbar that lets you impose markup directly, just in case you don't remember that "**" is the command to bold text.
You can set your wiki as public or private, so you can decide whether you want to share your content for collaborative work, or keep your musings to yourself.
Picowiki is a free service.