How did I never review Evernote? I only pretty much rely on it on my phone, web, and Windows computer (not sure about a Linux version). While not quite an open source app, Evernote does have a lot of appeal for usage.
So, a few years back, I used Google Notebook for everything. This was before Google Docs, so I took notes there, pasted links, kept phone numbers, everything! Well, eventually Google wanted users to migrate to Docs, so they stopped development of Notebook. At that point, I could move to Docs, but I did not want everything on Google. I looked around a little and chose Evernote. They offered an easy Notebook–>Evernote migration path that I jumped at. Soon I became dependent on Evernote more than I was with Notebook.
They really make things easy. Currently I have 57 notebooks I use. Those include ones for work (passwords, network settings, etc), family (computer specs, birthdates, etc), and home (car tire specs, my ‘loyalty’ card info, etc). I began only using the web-based client, but soon after they released a Blackberry client. That allows me an app that I can search for something quickly. Obviously I need an internet connection, but when needing a specific setting, IP address, or password, this comes in handy. Recently I also download the client app that allows me a desktop application to keep working with my notebooks offline, and sync when necessary.
I also like how I can take a picture using the Blackberry and post it as a note. Can you imagine how helpful this will be with the 8MP camera on the Evo I will soon receive? A great, useful app…that you should definitely check out!