Some people may view live wallpapers as nothing more than useless novelties that waste resources, but I really like them. They're more decorative than functional, sure, but there's nothing wrong with that. If it's nice to look at, fun to play with, or mildly entertaining in some way, then it's welcome on my HTC EVO, even if only for a short time.
The latest live wallpaper on my phone is called Liquid Physics. It was originally a simple port of Grant Kot's MPM liquid simulator done by jgittins but it was later tweaked and enhanced by quinbd over at the xda-developers forum. The EVO's accelerometer controls the movement of the particles, which move together and collide in wave-like fashion.
The latest version of the wallpaper (.apk at the link below) includes options to change the color and amount of particles, a blur effect, gravity sensitivity, and adjustable animation delay. This isn't something to use if your battery is running low and you're expecting an important phone call, but it's worth a look if you've got your charger nearby.[xda-developers]