I ran into a shiny Gligar on my second time of using the Pokeradar (is that whats it called), but I had no idea that there was a trick for chaining Pokemon. Once my friend told me about this I tried to do it and failed and never did it again. However, I did manage to capture a shiny Drifloon (luck, I know :D ), starly, geodude, shinx, gastly and a ponyta.
TG