In the past few months, we have covered plenty of smart door locks that can pair with your smartphone to make your life easier. You could always build your own though. Adafruit has posted a guide that shows how you can build a SMS controlled door lock using a Lockitron body, Metro Mini, and FONA 800.
Lockitron already has WiFi capability. You will just have to do a bit of hacking to pull this project off. All the parts and instructions are available on Adafruit.com.