I\'ve done some digging and the main ideas I\'ve seen floating around are using setuid/getuid and using the Authorization Services (which, for some reason gives me a symbol
Authorization Services is pretty well supported, AFAIK.
Here's a link to a tutorial (with sample projects!) which you can use to launch a small tool in which you can get admin priviledges and then you can call the setpriority API on your calling process (documentation linked for you).