I was always fascinated by the science laboratory hours at school, when we had to use microscopes to literally discover new words, and test chemical compounds and the ways they react with eachother.
I also remember how cool mercury was and how our incautious teacher had let us played with our hands in it, despite its toxicity. If you want to discover more about the micro-universe but you don't want to have the hassle of slides, drops of blood or samples of skins, give VirtualLab a try.
This application is funded by NASA and it is a digital microscope with many specimens you can easily download from the main page. You don't have to install anything, just click the thumbnail that attracts you most and the program take care of downloading it and make it available for you.
Among the specimens available there are human blood cells, penicillin, pyrite, meteorite, lunar dust, yeast, dog liver and human kidney samples.
Be careful though as some of the files are really big, more than 150MB and it will take ages to download them. This is because the images are really detailed and you can zoom in more than 150,000X.
For some images then, you can also select a portion and have a 3D rendering in another window.
Looking at the downsides I found the technique you have to use to navigate through pictures pretty unusual, and I didn't like the fixed zoom.
In fact, it is not possible to zoom in freely on an image, as there are just four fixed zoom levels you can choose from.
