Not as simple but well worth the extra weight would be org-mode. I personally find the vim-orgmode a balance between the full power of org vs my reliance on vim for day-to-day operations but I must admit I'm sometimes jealous of the power I see in emacs for this.
I have been a long-time Emacs user and I finally just started learning org-mode. I wish I had started earlier. Previously, I had used Zim to do my note-taking, but org-mode is just so much better in every way.
I have a feeling it's going to be my gateway into more heavy LaTeX usage for all manner of documents. The ability to evaluate code during document generation is a big deal to me.
Ha - I had that experience a few times: the first time I started using Org, the first time I started using the agenda, the first time I started using capture templates, the first time I started using code blocks, etc. Each time: Wow, why didn't I do this from the beginning.
