I agree with Tom that iPhoto is not the best place to archive your videos.
And I also agree that probably the format of those is not the most adequate, so at least you should let FCP X create optimized media for them.
Still, if you need to import from iPhoto to FCP X, there are a number of ways to do so:
1) Drag directly from iPhoto to an event in FCP X (select the movies in iPhoto, start dragging, cmd-tab to FCP X without releasing the mouse button, drop into the event name)
2) Create a new dummy project, choose the event where you want to store the videos as the default event for that project; in iPhoto, select the desired movies and hit Cmd-C (copy); switch to FCP X, make sure the empty timeline is selected, hit Cmd-V (paste); the movies will be pasted into the timeline and added to the event; you may discard this dummy project.
3) Create a Smart Folder in the Finder, containing all the movies in your iPhoto library. Then use this folder to import into FCP X as you would any movie file.
4) I am sure there are more options... :-)