How to check primary temp in 1g carboy?

I'm about to start my first batch this weekend, Rye IPA from brooklynbrewshop. I'm going to use a 1gal glass carboy for my primary but a little confused on how to check the temp of the wort while fermenting. I've seen photos and videos of people using a turkey baster to pull out the wort from the carboy to check temp and gravity, but how do you not spoil the wort by constantly removing the airlock?

I've been making my own hard cider for the past few months and now super excited to move onto the beer!

Put it in an environment that's around the fermenting temp and forget about it. Being that small it should equilibrate fairly easily. Most people only check gravity twice and that's after at least two weeks. The less it's messed with the better.

Buy a fermometer. They are cheap and pretty accurate.

-a.

+1 on the fermometer. It's a stick-on label type thermometer. Here is what they look like: http://tinyurl.com/alzu6zc . They work wonderfully, and are surprisingly accurate.

Thx everyone! getting a fermometer.