Have you ever wanted to write notes in the cloud?
No, not that kind of cloud. I'm talking about jotting down thoughts and having them sent to a server somewhere on the internet, to be retrieved and pondered over on any computer, wherever and whenever you feel like it. It's awfully convenient, and if you're a creative type of person (like, say, a blogger) or a wannabe creative type (like me), having this ability to immediately record a thought at a moment's notice is especially handy.
There are, of course, plenty of websites offering "cloud notes," but it's only today that I found one that I think really has the "whenever, wherever" aspect figured out. Diigo has a website, browser plugins, Android and iPhone/iPad apps, all of which can access the same store of notes, and a well-documented API so that any random person can tie into the service. All the hallmarks of a useful note-taking application.
Now, when I say "only today," I really do mean that I have about an hour's experience using the site and apps, so it's premature to say that I recommend it, but the signs are encouraging. They have a free account, so there's not much to lose by signing up to try it, at least.
Or you may want something different — not "wherever, whenever" coverage with fancy apps and plugins and the kitchen sync (see what I did there), but just a text box with a memory. For that, look to notepad.cc. It's probably one of the simplest and yet most useful webapps I've seen, rivaling even the minimal Google homepage. It doesn't even have a name! You just go to the site, and it redirects you to a random URL with an empty text box. Go back to the same URL later and anything you typed is still there. Easy peasy.