These Cross Orbweavers, Araneus diadematus, were mating in our front yard. We saw the female in her web (2, 3), then the male (4, 5) approached on a single strand of silk, twitching the strand as he cautiously advanced. A final dash, and he grabbed the female and apparently mated.
Number 6 is a video of the mating sequence. Once the movie loads, you can step through it frame by frame using arrow keys on your keyboard. Note the male vibrating his front legs as he advances.
Read more on spider mating at The Animal Communication Project.
In the Tintin Series, Tintin looks through a telescope early in The Shooting Star (1942) and sees what he thinks is a giant space spider. Turns out the spider is on the telescope lens. Professor Phostle identifies it as Araneus diadematus, the common garden spider. Two Araneus diadematusnamed Arabella and Anitaflew on the Space Shuttle (1973).