For note taking I like keeping things simple such add just using a text editor, but there are occasions when it's useful to keep a photo (such as when you're at the datacenter and need to remember which nics you've just plugged in the back of a server) and text only just won't cut it.
That's where Evernote and my favourite Catch notes come in. They also have the added bonus of syncing with the cloud so it's easy to get the content when you're back at your desk again.
I prefer catch mainly because it can be moved to sd card (which breaks widgets) and it has a small lightweight widget for quick notes.
Well designed, easy to use and rather useful.
