manipulating custom fields

[youradultworld]

This hack may sound impractical, but it will give me the insight on how to perform many tasks. Lets say for instance I create a custom field to enter your age. So if everyone has their age, and I want to list members and show the difference in their age and my age, so in other words the members list would show how many years they are old or younger, how would that calculation be done?

I am hoping to gain how to get the custom field information for other users as well as to compare it with my own same custom field.

Any help appreciated.