I have a Maverick ET-73 (ET-732 inbound from Amazon
) for monitoring long smokes. I use a Taylor Weekend Warrior (http://www.taylorusa.com/weekend-war...ermometer.html
) when I want to poke something in the meat and get a quick reading. It's probably not as fast as a Thermapen but it can be had for about $15 on Amazon. I am not a pro and it is fast enough for me.
It's good to develop the skill to cook w/out instrumentation but good instruments can help you to get to that point. Plus, with the ET-73/732 probes in the meat, I can monitor progress w/out the need to open the smoker.