I discovered a way to use Apple's "Find my iPhone"® feature of MobileMe® on iOS devices other than the iPad, iPhone 4 and iPod Touch 4G.
The way to set it up is to:
1. Enable it using one of the supported devices (i.e. a friend's iPhone 4) temporarily; using your Apple ID®.
2. You will need to look at this page and follow the instructions on how to set it up.
3. Remove that account on the device you just enabled it on.
4. Go to your older device (the one you want to enable it on) and enter the details that you used to enable the feature in the first place. It should then be configured properly.
5. You can access the Find my iPhone® MobileMe® portal at MobileMe Login or using the Find my iPhone® app. Login with the same email address and password as your Apple ID®.
