I might be behind the times but I just found this remote control for speaking engagements - the Logitech Cordless 2.4 GHz Presenter. It has all the bells and whistles that most other remote controls have. However, this one has a countdown timer (silent vibration warnings at 5 minutes and 2 minutes).
I've been on the podium and know the value of a good wireless device. I love the fact that this Logitech model has a countdown timer on the remote. Too many venues have the clock only on the lectern. Good speakers, I believe, don't use a lectern but if the clock is either there or on your wrist, I will use the one on the lectern. Having to circle back over to the lectern to peek at the time to make sure I'm where I need to be in my presentation just gives me something else to worry about. When you are speaking, the only thing you want to worry about is delivering for the audience.
The Logitech is under $70. Read the reviews here.