Quick Question

I have a 5th generation, iPod, 30gb... and every so often when I am scrolling through my long list of albums and songs, sometimes a little semi-transparent box will appear in the middle of the screen, and will let me scroll through by going to the letter of the alphabet that the album\song starts with (like, you can go through your list by the first letter of the song)

And I was wondering if it was possible to get this to show up, not randomly...