How to determine the current run-level

This is really basic newbie stuff I suppose, but more than once I've needed to know the run level but I can't remember how to find it because it doesn't come up that often. Anyway, who -r will tell you the current run-level, along with the number of times the system has been at this level, and the previous run-level. On HP-UX you can also use /sbin/getrunlvl, though I'm not sure why you'd want to.