How do I run a program as it's owner?

[Dan Anderson <dan@mathjunkies.com>]

I know there is some way to allow a program to run with permissions of
it's owner (i.e. root) but I forget how to do this.  What am I
forgetting?

Also, if I create a crontab file, will all programs run as nobody or
with the permissions of the owner?  And is it possible to see whether or
not a crontab entry was successful by viewing a log of some kind?

Thanks in advance,

-Dan