Manufacturers of security systems have started to offer apps (usually free) so you can press buttons on your iPhone to arm and disarm your system. Many apps also send instant alerts (sometimes with video attached) directly to your mobile device and allow you to review changes, like a tripped sensor. Check out MyKeypad from Honeywell (pictured), eKeypad M1 (for Elk-brand security systems), Alarm.com and Platinum Protection. Some of these remote access apps only work if you subscribe to a monthly monitoring service; check with your security dealer.