Here's a walkthrough of ipython, bpython, and bipython:
The screencast is 20 minutes long, but here I'll play it back triple speed. There's no sound, and you can pause at any time (lower left corner), seek around (put your mouse over the last line to reveal a progress bar you can click on to go to that portion of the screencast). bipython portion starts 10 minutes in (half-way). You can also select / copy portion of the text as you like. Changing the browser font size in the usual way works, too. (click here if the embed didn't work, or if you want to watch it in real-time, without the speedup).