Just lately, the last two days or so, I began noticing... something. It might be a miss, hesitation, exhaust hiccup, something like that. It happens sporadically, and only at idle, and it's starting to happen more frequently, maybe 6-8 times per minute. I've noticed no change in RPM's when it happens. My xB is a bone stock '06 with 19.5k miles, 5 speed, and of course JUST out of warranty.

Any ideas on a cause?

my Tc occasionally does the same thing ive read its a dirty throttle body

Try to rule out the usual suspects. Is your check engine lite on; are you throwing any codes? Have you checked your spark plugs (check for unusual wear, gap)? Is your air filter dirty? Do you notice any new leak stains where you park your car? Do you have a sound system; how's your battery voltage? If more than 3 yrs old, it may need to be replaced. Bat should show 12v cold and 13.5-14v running.

bearcave is like nostradamus. Came back on to post what I ended up doing-

checked my plugs (fine), changed the air filter, used dry gas on a full new tank of 93 octane. Hesitation is gone. It was one of those three things. Wish I had done them one at a time to be more precise.

Thanks for the replies.

One thing I do notice is that the maintenance required light does blink/flash a few times after I start the engine, but it goes away. From what I recall reading, this is just a Toyota safety thing, right?

NOT your plugs then and not the air filter it was some dirty gas maybe just water . . . the blinking Maintenance Required happens every 5-6k miles and will start by blinking after starting and then will stay on at the set mileage. Usually reset by the Toyota/Scion service when the oil is changed or you can reset it with the trip odometer button.

Yep, the blinking maintenance light is just indicating that you're close to the oil change increment.