I've been using this goofy little bell for a number of years now and I love it. By attaching it to a dry erase marker and using the marker to write the page number I want everyone to find, I no longer have to do the Old School thing of announcing the page number verbally.
Fewer spoken words; a bit more fun. Always a good combination.
If you'd like to read about how the whole idea was created, check out the Birth of a Notion post in the new Thoughts on Teaching link.
For a shorter, more how-to-do-it version, check out Page Pen in the Classroom Tips link. You'll also find some modifications of the basic idea that have resulted from the experience of sharing the idea at seminars.
Bonus Feature: You'll never again here a student ask,
I think that's worth a buck.
Page Pen bell
19 x 25 mm
comes with rubberband