Nice idea. My first suggestion is: Give the textboxes a one-color background that has more than 50% opacity. Otherwise the background image will allways be a problem no matter how you change the font colors. Just an example: Making the text red so it sticks out better might work for the average person, but ask a color-blind person how good of an idea that really is.
There's a reason why professional webdesigners do NOT put text directly over actual background images, but instead allways have a color background to it that is contrasting well with the font color and is at most semi transparent
Agree, Also maybe try either shrink the background image or put one with better quality up. Id rather wait a few extra second for it to load than have a pixelated background image.
Also the scrolling image with the massive background image just seems a bit too busy IMHO.
Last thing :
Bitcoin Help
An easy guide for people new to bitcoins.
this section is really not easy to read, especially considering it your punch line and title.
