They're cute. They're pretty. They don't do much.
When teaching myself technologies, I prefer not to just aimlessly mess around. I learn better when I have a project in mind, even if a useless one.
Most of these use no images; instead, I've been testing the limits of Unicode glyphs.
Some Like It Slot
A virtual slot machine.
Deck of CSS Cards
Draw playing cards using only CSS and Unicode.
Draw Tarot cards using only CSS and Unicode.
Get a tarot reading, using the CSS/Unicode Tarot cards.
Turn your text nʍop-əpısdn.
Dynamic CSS color mixing.
Ooh, shiny buttons. More color mixing.
Animating bubbles with CSS borders and jQuery UI.