In The Lord of the Rings, when Legolas the elf succeeded on his spot check, he was the one to announce to his friends that he saw riders in the distance. There was no voice from the all powerful DM in the sky that informed Aragorn and Gimli at the same time, and they learned only when Legolas told them. 

As a DM, I would like to let my characters announce their discoveries to the group, in order to let their characters interact, increase the immersion, and let my players have the fun of exposing what the characters discover. 

Unfortunately, doing so seems difficult, and unpractical. I thought about secret notes, but I fear they would down the game if I have to always write things down and send them to someone. I thought about texting, but I would rather not have cellphones at my table.

So, what are strategies to let my characters announce what they know in a way that enhances the game instead of bogging it down? 

Feel free to re-explore the two methods I named here, as those were simply impressions on my part, and I am not ruling them out. Also, don't be afraid to tell me it can't be done if that's the case.