Let me go ahead and put this out there- There's a whole lot about Notational Velocity that I don't understand. I've only been using the thing for about a week, and I'm definitely an amateur at it. Merlin Mann over at 43folders is probably the guy you want to talk to about this. When he posts more about how he uses it, then I'll definitely talk about it and how I plan on integrating his tips into my workflow.
That said, NV has a dead simple interface that is the heart of how I use it. I feel like I'm the leading edge of what I'll call the Generation G. We tend to eschew hierarchical organization in favor of relational organization and search- we're the Google Generation. We also like to have our stuff accessible in every conceivable mode- My data is less valuable to me if I can't push and pull from my iPhone, and from from Macbook, and from my Work PC. We all crave our own personal little cloud, and we do our best to cobble it together. The less we have to use the mouse, the better.
So my first post on NV is going to be about the App itself. I'll talk about integration with Dropbox and Simplenote later.
NV is based on the notion that you like to write things down in text files. You don't care about check boxes, or pictures, or any of that crap. Just text. In some cases, that means it's only the starting point for my workflow, the place where the copy of a blog post is worked on and saved but the images used are not. In others, it's where notes or To-Do lists are kept. NV does it's best to be as transparent a tool as possible; it tries to let you access, search, and edit your library of text files with minimal fuss.
Your best friend in NV is the search bar. It's where your cursor starts out, and it's what lets you access your library of text. As you type, NV will start listing files that match the search. NV seems to focus on a title search, but will also display titles that have matching text inside them. It will auto-complete potential title matches as you type. If it auto-completes the title you're looking for, hit return and go nuts. It'll place you into that file and you do your editing.
If you type up something in the search box that doesn't match any titles, though, something cool can happen. Hit return and start typing, anyway. NV will create the file and you're on your way. This is why NV is cool; it lets you find the file you're looking for or create the one you want, dead simple and quick.
NV uses an Incremental Search engine that I'm still getting used to. It does, however, let you search to any part of a file just using the keyboard. And that's important; using a mouse is an interruption of the creative writing process, in my opinion.
Now, here's another awesome thing: Storage. NV allows you to choose to store your notes in an optionally encrypted database, or as a flat file structure in a specified folder. And why is that cool? Because it lets you modify these text files from outside of NV, and do things like sync them to Dropbox for backup and access. Anything you drop into or modify in that directory is reflected in NV. It's a transparent, plain-text API to the budding text library that you will soon use to replace your brain.
All that's well and good, but the question has been asked; "How do you use it?" And I will answer, again stressing that I am an amateur. I use the titles of my text files to reflect their relationships to a particular project or area of my life. Files generally start with "Work:" or "Personal:" or "TA Blog:" and go from there. This allows me to type in these key words in the search, and list the files that fall into these categories. It also ensures that those key words are there if I'm searching for other things, such as "work "high priority"" or "personal expense" to find Work: files with "High Priority" somewhere in them, or Personal: files with the word Expense in them. You can build it out from there.
What this allows me to do is pull up the things I need to find and make notes on very quickly. If something occurs to me and I need to switch to another file, CMD+l will put my cursor back at the search again. It's so easy I don't have to think about it, and that's the important part.
I should probably also mention that NV automatically saves as you type. You never have to worry about remembering to hit a save key; changes are committed as you go.
And so, that's how I use NV right now. I'm sure it'll evolve as I look for ways to integrate it with Quicksilver and services in Snow Leopard. And I'll write another post soon on why syncing with Dropbox is awesome and why SimpleNote on the iPhone rules.