<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by Mrukk:
and have 18,000 or so miles at the moment.</font>
One caveat: miles earned does not equal status miles. Subtract signup bonus, partner miles, and (for most airlines) class of service bonus and only look at miles earned by sitting in an airplane seat to determine how close you are to an elite level.
Different progerams differ, so take andrzej's advice and visit the DL forum with your specific Q's.