There is a nice piece of code[1] that you can utilize to measure distances between coordinates. I used a modified version in my app and it seems to be pretty accurate. If you are just basing your distances from the center point of your office, using the radius of the circle should be pretty straight forward. AIR's access to the gps works good in both Android and iOS.
[1]http://snipplr.com/view/58443/ -- View this message in context: http://apache-flex-development.2333347.n4.nabble.com/Geo-fence-in-Flex-Action-Script-tp47043p47125.html Sent from the Apache Flex Development mailing list archive at Nabble.com.
