Brick paver edge border question
I'm in the final stages of rebuilding a paver patio inside an irregularly shaped rock garden. The old paver bricks were cut to shape along the rocks. The rocks seemed to settle causing the edge bricks to move and the patio deteriorated over 15 or 20 years. Many bricks cracked so I started over with new bricks and a new foundation. I've changed the paver layout to incorporate a border and have left a gap to most of the rocks. Most of the gaps are too small to fit standard edging/stakes.
Pictures here: http://picasaweb.google.com/duncan.spillman/20101025#
Can anyone recommend what material(s) to use to close the gap beyond the border? Would concrete be a good selection? Would that hold the bricks in place over time?
Here is a link that might be useful: Edge picture