Aerosnap feature
Finally (sorry, ronniew). The window stacking to the edge feature, explained and simplified for Lubuntu prior to 13.04 (where it is, in fact, already implemented).
Not very sofisticated, keyboard driven only. The next version of Openbox will support this drag’n’drop features, so we could enjoy as XFWM or Metacity users do. Available at Tips’n’Tricks section.