Not nearly as cool as all the other stuff here, but still my favorite piece of tech for myself:

IMO, Vim + Markdown is one of the best ways to take notes, brainstorm, or just explore ideas. However, I found the questions of "Where should I put the notes in my dir hierarchy?" and "How do I find the notes again?" and "How do I ensure I have my notes across all devices?" to be inhibiting.

I wrote a CLI "journal" tool that says "forget putting them into folders", dumps all the Markdowns into a single Google Drive folder, and instead focuses on providing really good search.

Now, in my day to day, I can do "journal new some-meeting-with-dan.md" and I get a fresh Markdown. I can also do "journal find" to search by name, date of creation, or tag, and then open notes in either Vim or as rendered HTML in Chrome (for copy-pasting). Behind the scenes all the information is just encoded in the filename (so it becomes "some-meeting-eith-dan~2023-04-23T22:10:23~tag1,tag2.md", with no extra DB needed).

I'm also now trying to rewrite the frontend as a Charm TUI, which is another whole fun growth path!