Tonight is the night (actually, tomorrow morning at 2am) that we turn our clocks ahead by one hour, and when we should be replacing the batteries in our smoke detectors (and carbon monoxide). This year, with the change in the smoke detector regulations, you should consider replacing any of your smoke detectors that are near (within 20ft) a kitchen or a bathroom with a shower with a photoelectric model.
Most smoke detectors that are currently installed in homes are of the ionization type. They work very well, but are prone to going off due to cooking vapors and steam from a shower. When this happens, people tend to remove the batteries to shut them off, and ultimately forget to put them back in leaving everyone in the home vulnerable to a fire. The photoelectric type is not as sensitive to false alarms, therefore the batteries won't be taken out, leaving them ready to do their job at all times.
Though the new law that goes into effect in April only applies to new construction and homes that are being sold, you should take the initiative and install the photoelectric detectors now.