tyranisneasel: (This is hypothetical.) Since computers are deterministic machines, it's impossible for them to generate truly random numbers. I'm hoping that the game generates certain PVs (Personality Value, a hidden value responsible for things including natures, genders, and shininess) more often than others. Since shininess is determined by a hidden value similar to your trainer ID, if this is the case, games with certain such IDs will tend to generate shinies more often than others. By resetting my game totally on occasion, I don't raise the odds of seeing a shiny Treecko, but I raise the odds that, once I do, I will see shinies more frequently later on. (This is hypothetical.)
King Kobra: "Miss Cake" is the name of my Scizor. (female) I got the idea from Runa's Scyther who battled the L140 Kabuto. As for the D/P sprites, if you were to check my sig on SPPF, you would find that I had reparied the sprites from the official D/P screenshots. After that, recolouring them is trivial. (The album of repaired sprites (which can be expected to grow as more screenshots are released) can be found here.)
Exokriz: I'm sorry to hear that about the Weedle and Onix. On the bright side, if the theory I described above is true, you're bound to run into some more shinies! ^o^ Raise a False Swiper ASAP.
~2986 Treeckos. You'd know if I found a shiny, even if it's a Zigzagoon. >,>