There are tons of open-source projects, on SourceForge, Google Code, etc. If you check a project, most likely you see the screenshots first (don't be ashamed, to look at a screenshot is human). And there lies the problem. There is a fairly small amount of coders that are both very good at writing codes and composing good-looking screenshots.
So we had a terribly hot weekend in Oslo. Too hot to be outside the whole day. So after populating the wonderful weekend with banana brownies (I still favor the one with mango, though), fresh chocolate waffles (let's see if I can still continue the Sunday morning waffle tradition), huge delicious pizza (as usual I underestimated the size), pasta bolognese ala myself (but still can't beat the best one, so I was told), every now and then my own interpretation of alcohol-free SOTB (guess what it is. hint: a cocktail of course), and finally some of the worse sushi rolls I ever made (they got it right when they say practice makes perfect), I still have some free time. Then...
I sat down and checked again this old piece of code, Screenie, that I never had time to finish (note to self: do that more often and clean up the junk). It was a tool to compose a screenshot with some style. By style here I mean of course just copy Apple. Why? If you check e.g. Apple Keynote site, you see the proof that simple transformation and effects can make a big difference. What Screenie can do for you should be predictable: to create a screenshot like that.
Assuming you have Qt 4.4 and git, here are the steps:
git clone git://github.com/ariya/screenie.git cd screenie && qmake && make
(Likely you need qmake-qt4 for (K)ubuntu and Debian).
Basically you have a window where you can drag-and-drop an image from Konqueror (either local file or from the Internet) and place it there. You have three spots on the screen to fill. Tweak the parameters to achieve the 3-D goodness and translucent reflection that you want. Finally right-click to save the result.
As some Apple web pages show, there are certain cases where you want two images instead of three. So use your imagination and the check boxes are at your disposal. In the following example, I just drag-and-drop the two Plasma screenshots (one, two) I have on my Flickr straight from Konqueror. Don't you agree that visually it does make a difference?