One of the things we discussed at Sharkfest this year was providing a common location for users to share their lua scripts, colouring rules, display filter macros, and other useful plugins.
Discussion is still on-going as to whether we will provide a proper git repository or some other management site, but in the mean-time (and partly to judge the popularity of the idea) we've created a simple wiki page where people can upload their contributions:
http://wiki.wireshark.org/ContribIf you have such useful items to contribute, please share them and make everyone's Wireshark experience better :)