Well I don't exactly know what you mean by keying, but I think you are trying to drop a lot of pictures into the timeline one by one and sequence them to create a DVD of your vacation. If that is the case, here is a quick simple way to do that:
I'll assume that you imported about 200 or more pictures.
First, select all the pictures in your event browser that you want in your video. Either rubberband around them all or select the event and choose "select all". Hit "E" to immediately place all of them in the timeline. They will appear in the timeline one after the other, but probably at a duration longer than you'd like.
Next, rubberband them all in the timeline and hit Control-D. This will bring up a duration that you can change. The timecode window will highlight and simply enter 400 (for 4 seconds). When you hit enter, fcpx will change the duration of every photo in the timeline to 4 seconds.
Next, rubberband around them all again and press Command-T. This will place a simple dissolve transition between every photo in the timeline.
Next, choose some music you like and drag it to the timeline beneath the photo clips. Use your own iTunes music or something from fcpx in the music browser.
Finally, select all the photos and music in the timeline and hit Option-G to convert that sequence to a compound clip. (You don't have to do this, but it will provide one single clip in your timeline browser list as opposed to 200 or more. That one clip will contain all your photos with the underlying music beds and a transition between them.
Finally, add your vacation title to the beginning and any credits you want to the end. Select SHARE from the menu and create a DVD of your sequenced photos. You don't even need to render anything as this will automatically be done upon exporting to DVD by fcpx.
That's a fast and easy way to provide a sequence of pictures on DVD. Obviously if you need to color grade any of the photos, that would need to be done one by one and before you apply the transition.
Not sure if this was what was taking you so long, but hopefully this helps.