Have just been playing around with Zoho Notebook - and I like it!
It is a similar sort of application to Evernote, but on the face of it, it appears to be a bit more user friendly and intuitive than Evernote. Here is a video showing some of the things you can do.
Any negatives? Well, the extension for Chrome doesn't work in Google pages, so you can't clip a Google page directly into your notebook from a web page. You can still put the web page in by adding the URL, it just takes a little bit longer, and means you are switching from the web page you are viewing, to your notebook. The extension does work for other websites however, and works well, giving you the options of saving the URL, highlighted text, or a screenshot.
A small drawback is that you don't seem to be able to tweet directly to it, the way you can with Evernote. But that may be just a matter of time.
That is all I have found so far, but I feel the need to explore further. Uh oh - new toys!