A nice feature of working in X on Linux is copy/paste by selecting (copy) and pressing the middle mouse button (paste). When I'm sometimes forced to work in Windows I realise how much it replaced my old ctrl-c/ctrl-v habit. I also use the trick with Mozilla Firefox to load an URL that is not clickable, because there is no anchor element around, or because it's in some textfile for example. You can even use a word instead of an URL to activate the built in google-"I feel lucky" feature. After selecting the URL you only need to middle mouse click somewhere on a "neutral" place of the Firefox canvas (middle mouse clicking on objects like links, buttons or textfields cause a different behaviour).
Very handy indeed. But after my switch to Kubuntu Linux the trick stopped working. After being a bit annoyed I asked google and found the solution on http://thomer.com/howtos/paste_in_firefox.html:
- open the about:config page (type
about:configin the location bar) - search for
middlemouse.contentLoadURL(e.g. typemiddlein the filter on top of the page) - make sure it has a value
true(double click or right click for a context menu)