In order to be able to do a good job porting OOo4Kids on Sugar, we tried to try it out with one project we've done during school. Nothing big, only a "Raytracer" that draws a Sphere in 3D (that does far much than that, but we will only use this fonction for now).
First, we made a proper compilation on the XO-1 (recompilation of our libs and the project itself, not that hard) and then tried to add it to the activities (and by the way adding our activity to the journal) of Sugar using the HelloWorldActivity as a sample, that worked but we had a problem: it opened a window for the activity and one another for our Raytracer, so that was quite a mess.
Then we tried the Sugar Coating method (by the way, thank to the Sugar-labs who gave us this hint on #sugar). The sugar coating is a method that adds a Linux binary to Sugar Activities (available on http://wiki.sugarlabs.org/go/Running_Linux_Applications_Under_Sugar and on http://www.catmoran.com/olpc/sug). We that followed what the script was telling us to do and the first problem was solved but the Sugar coating doesn't handle the journal and the toolbox, so we will have to take that from the HelloWorldActivity tutorial and add it to the Sugar Coating.