Markers can be extremely helpful – but haven’t been very versatile. Final Cut 7 includes an update on the markers that provides all kinds of goodies. There are new colors for the markers. You can easily move them- and not just awkwardly to the right. You can edit them without stopping playback. You can export them. Ripple Training has a good overview of all the new features with markers.
Find the tutorial here – under Final Cut Pro 7, click on the link under “Improved Markers.”