I will try to explain why I don't want to pay for note taking apps. Just an insight, I am probably wrong. Why ramble on like this? Maybe there is someone who can point me to a nice app that I can use. The problem with most these apps is that I can't just point at a directory where the app should organise my files. I am not looking for something that saves my files to some strange (proprietary) format in an invisible…
http://brettterpstra.com/projects/nvalt/
(nvALT adds Markdown support and a few interface adjustments)
Point whichever NV you use to a directory of txt or markdown files in your Dropbox. NV is nimble and lightning quick, and it excels at super-fast search. Don't even bother with tags, just search.