[bee_rider]

Pencil and paper is the best environment for working out anything at all difficult.

It would be nice if there were an environment to take a picture of written pseudo code and/or equations and spit out some matlab, numpy, or eigen code.

[OkayPhysicist]

I'm partial to chalk, myself. The process of filling a board, erasing the parts that are no longer needed, then filling the board again distills your work down to the key ideas. And I just hate dry erase markers.

[globular-toast]

Yep. I know a problem is interesting if I reach for the pencil and paper. It's been on my desk today, which is good.

My PhD supervisor got me into writing with pencil and paper. I wrote near enough my entire thesis that way. It was only transcribed to computer for typesetting after it had been proofread at least once.

[ahartmetz]

I like nothing (a walk) and a plaintext file when I need to remember many details.

Computers are distracting.

[nextaccountic]

I don't know about paper, but having a large whiteboard in your room is amazing. A wacom tablet is great too.