well, thanks for the kind words!
first off, the '*' is just what it looks like, a multiplier. you must do either '*1' or '--' because with the syntax of:
=sumproduct(istext(a1:a4))
with something like 'T,1,2,3' in A1:A4 respectively, will bring back:
{TRUE,FALSE,FALSE,FALSE}
either above option will coerce excel to translate it's *boolean* (true=1, false=0), to numerical value, for a computational value. it's actually pretty slick.
so both methods work. AND you must have at least one of them. as Will points out, there are many methods.
hope this helps!
ps - and i learned almost everything i know from forums like these!!