I wrote a post a while back that talked about how to copy animation keyframes between layers in Adobe Photoshop. If you’re interested in this topic and haven’t read the post yet, please go ahead and do that. I’ve included lots of great information in it.
A fellow named Kevin just left a comment for that post where he suggested that you can go one step further than simply right-clicking on an individual keyframe or using the Ctrl key on your keyboard to select multiple keyframes and then right-click on one to copy all of them. Kevin suggested that you click and drag across multiple keyframes to highlight them easily and then right-click to copy them. I thought that was a fantastic idea and that it mimicked the type of action we can take in Windows when trying to select multiple files or folders. I wanted to mention it here for you to do with as you please. Enjoy!