Hi Tobias,
I've found your HashTagsPlugin very interesting and may be helpful to weave a meaningful network of knowledge in my notebook, and I have tested it on my TiddlySpace/TiddlyWikis with working results (too bad Chinese characters can not be used as hashtags, but I guess it's for the purpose not to overload the plugin function right?).
I also found that the "preview" macro of the plugin while very useful, may conflict with the PreviewPlugin (
http://www.tiddlytools.com/#PreviewPlugin) of Mr. Eric Shulman, so here is for your information.
Cheers and thanks for your innovations!
G.J.Robert
Taiwan