Wonderfl lets you build from scratch, lets you copy and edit scripts from other users, and you can download and save scripts of your choice to your computer. The site also features a flash viewer; on the left-hand side of the screen is the code, and on the right is the preview screen--just hit start and you're ready to go! The site features games, awesome visualizations, and other miscellaneous Flash code tidbits.

The first example that you need to check out is This Flash game displays a number in binary and you have to guess what the number is in decimal before the timer runs out.

If you're into shooting games and you like a challenge then I'd definitely check out . It's your standard space-shooter game, but it's very fast so you might want to keep your finger on the space-bar (the "fire" hotkey).

Another...um...interesting, and weird, game is . You take a "sword of light" with your mouse and slash apart cactuses as they come flying at you from the distance. I found this game completely pointless, but it easily supplied me with about 10 minutes of entertainment (ahem).

There is also the script which is definitely pretty entertaining. You are given two awkward vibrating balls; you can then grab one ball and throw it at the other ball. The balls can do all kinds of funky things like stick together, crunch into smaller shapes if thrown hard enough, or simply provide you with untold amounts of time consuming bounding off the walls.