We test our smoke detectors and change the battery (whether it needs it or not) annually on New Year's Day. We found this way to work for us since we usually stock up on batteries for Christmas.
We periodically test the smoke detectors through out the year as well when we think about it.

We test both detectors the first of every month.

Never checked mine ... (walking over to check smoke detectors)

We change ours every 6 months when we turn clocks forward/backward for daylight savins time.

Like once a month unless if beeps

I check it every Feb. 29 (every four years) I've only had 2 of the 4 houses I've lived in burn down... 50% isn't bad.

I try to change our batteries twice a year when we change our clocks. I'll admit sometimes I do forget so I answered once a year. I did not realize they should be replaced every ten years. I bought ours when we bought our house in 2001, it's time to replace.

I check mine every time I cook. LOL Seriously, i check mine often.

Also, don't forget about the importance of getting a carbon monoxide detector.

Guys, and girls, As a firefighter myself and one half of my 2 man fire prevention team I cant stress enough to PLEASE check your smoke detectors at least once a month. The standard for changing the batteries is twice a year; once at turn your clocks back, and once at turn your clocks forward. The smoke detectors are starting to become a thing of the past. Margaret touched on it about how do you know when they work, when they say dinner is ready. Also, Margaret is correct about the carbon monoxide detectors. Carbon monoxide is colorless, and odorless, it is the silent killer. 2 symptoms are headache and nausea; you go to sleep at night with CO in the house and you dont wake up. If you or anyone you know has questions, concerns or comments, call your local fire dept. Or, call your boro building and the can direct you in the right direction. http://www.usfa.fema.gov/downloads/pyfff/smkalarm.html

Well, Roger, since you had me stumped on this, I dug into the world of google. What would we do with out it. I will provide you with the link best suitable for your questions and concerns. All i can say is the people using a gas generator inside, are taking a big risk. The obvious sign of carbon monoxide is a running car in a garage; never do it, even if the door is open. Also, you can get CO readings from your hot water tank, too many candles left lit in an enclosed tight space, and so on. Here is the link it is very informative.... http://www.cpsc.gov/cpscpub/pubs/466.html

mine get checked often when my wife is cooking.

We used to replace our batteries every time we changed the clocks back or ahead. We always tested the batteries and they were always still good. A couple of times we did not have enough batteries on hand and then could not remember if we ever changed them or not. That is when we decided to make it a New Years Day event in our household since we always had the batteries in the house to do it. I know they recommend twice a year but once a year is better than not having the batteries and not getting the job done at all. We also write on the battery with a sharpie the date the battery was changed. We then test ours frequently through out the month.
We also have a CO detector on each floor.

"FIREFIGHTER GANGNAM STYLE"
Brace yourself this is new and creative way to promote fire prevention month! This is the South Baldwin Fire Company where my son is a junior firefighter. Be sure to watch the video til the end. Charitable donations are welcomed.
http://www.youtube.com/watch?v=uYNkip68dig