Bottom of the cup.
I drink maybe two cups of coffee each day. The travel mug I use for work holds just the right amount and I usually don't finish it until 10:30 or 11 just because I'm so distracted with other stuff.
The weekends are another story. With no travel mug or schedule (other than kids) to take my attention, I power through coffee and I find myself at the bottom of the cup very quickly.