You can use PKHeX to import these images as C-Gear backgrounds for your Pokémon Black, White, Black 2, or White 2 save file. All (except the secret ones) have been tested to import successfully and look great in any game. Show off to your friends!

That's right, real-life physical bookmarks! Print 'em out, then cut 'em out! You can laminate them too for extra polish. All are 2" × 6", make sure that you print their sheets out double-sided and set to flip along the long edge (usually the default).