I found out by coincidence that it is possible to select a piece of text on some webpage and drag it into a TW. Into an editor window just copies the text, into the ‘green zone’ imports the text (formatting, links and all) into a new tiddler. This does not work well on text from a PDF file, unfortunately.
Also, copying an image somewhere and pressing ctrl-v in a TW (outside any editor) imports the image as a new tiddler.
My question: is there an overview of all easy methods of importing information into TW?