You can organize your work flow through virtual desktops(and have them all share the same activity) or through kde4 activities(have one virtual desktop and multiple activities) or multiple virtual desktops with multiple activities ..whatever works for you..
Ah. It seems as though I again do not 'fit' either style - my pattern of usage, regardless of whatever "activity", is to treat all desktops similarly. I do however wish to have different background images upon each, as such does aid in visual identification - besides; having only one background image quickly becomes rather boring, I find.
In that regard, however, I did have one somewhat-related question: shall linux (in general) ever gain the ability to display animated desktop backgrounds? Yes, I do realise that such are generally regarded as being annoying; however, people do ask me that question regardless, and as yet I have no answer to respond with. Be it an animated .gif, or an actual video file of some sort, or even a URL streaming webcams or pornography or whatever... some do pose this question to me, all the same. How should I answer?