So you want to get in on the latest Aqua craze and liquify your life? There are a few ways to create Aqua buttons, ranging from hard but rewarding (Photoshop files from scratch) to somewhat easier (copy/edit an existing Apple button). However, this is by far the easiest way I've found to do it.
A Japanese author, whose home page only hints at what his/her name might be ("Hide's Room"?), has developed Liquid Buttons. The button in this posting was created in about 10 seconds in Liquid Buttons.
You can download the program from "hshioura's" page on mac.com and try it out for yourself.
The biggest problem with the program (for us English speakers!) is that it's in Japanese, and you'll either get gibberish or Japanese text in the dialogs and menus. However, it's very simple to use, and trial and error will quickly lead you to the right way to create and save your buttons. A quick hint to get you started: design the words and colors you want, click the lower-left button, and then click the lower-right button to save your work.
Quite fun! If anyone knows more about the author, I'd love to provide more details...
Mac OS X Hints