You could do this with array formulas. Instead of hitting Enter to
finish the formula, use Ctrl-Shift-Enter to add the curly braces to the
array formula. If the range of values is in cells A1 through A10 and
you want to disregard all values equal to or greater than 25, use:

{=AVERAGE(IF(A1:A10<25,A1:A10,""))}
{=MEDIAN(IF(A1:A10<25,A1:A10,""))}

For more info on array formulas, see
http://www.cpearson.com/excel/array.htm

Hope that helps.
- John
www.JohnMichl.com