I know that iHerp is currently developing an ANDROID based tracking program, and i am almost certain this is already active for the iPhone users.
I'm not sure if you were going to have a different approach then just tracking but for those who don't know about it, its worth checking out.
You can click the link HERE or click the signature in my comment to link to my current ball pythons tracking sheet.
Also iPhone users just search iHerp in your app store...