If you’re looking for a wireless remote, consider the Logitech Wireless Presenter R400. Bill C uses this and it’s simplicity and small size appealed to me and at $40 it’s inexpensive.
There is a R800 model which sells for twice the price, but it also has twice the range. The R400 has a range of 50′ and the R800 has a range of 100′.
You’re rarely more than 50′ away from the laptop so the R400 should do fine.
It also has a button to make the screen go black which is a good way to bring back the attention of the audience to yourself.