Steve Sande and I have been collaborating on "Talking to Siri," an ebook that will soon hit the Kindle store. It's a how-to that will help you get the most done with your Siri intelligent assistant.
One of the questions that people keep asking us is "how do I spell out the word 'comma' or 'period'," in other words, how do you dictate the literal word instead of punctuation.
Fortunately, there is a solution for this. It's not a clean solution or an easy one, but it can be done. To type out comma, for example, you dictate no caps on, no space on, C O M M A, no space off, no caps off.
This tells Siri to start a forced lower-case mode without spaces. You then spell out the word in question (comma, here). At the end, you return to normal dictation mode by disabling that mode.
Be aware that Siri looks for context. It can differentiate between "The Jurassic Period" and "The Jurassic." (see that period there?) during dictation, preferring the former because the word finishes a phrase.
Like this tip? Have some more Siri power-user suggestions? Let us know. Join in the comments.