A custom URL scheme provides a programmatic method for launching an iPhone app and invoking a particular function. The URL scheme for both Blurb and Marquee allows an iPhone app or a webapp to launch either Blurb or Marquee and display a large scrolling text message. For more information on URL schemes, please see Apple's iPhone URL Scheme Reference
Tap from your iPhone or iPod touch for a demo
eg. marquee://playMessage?text=Hello&textColor=red&timeLimit=60&returnURL=http://www.yodelcode.com
All parameters optional except for text.speed: [0..10] default = 5
font: [Helvetica, Helvetica-Bold, Helvetica-Oblique, Helvetica-BoldOblique] default = Helvetica
textColor: [aqua, black, blue, fuchsia, gray, green, lime, maroon, navy, olive, purple, red, silver, teal, white, yellow]
default = white
backgroundColor: [aqua, black, blue, fuchsia, gray, green, lime, maroon, navy, olive, purple, red, silver, teal, white, yellow]
default = black
timeLimit: [10..3600] default = 300 seconds
returnURL: will be invoked if message play is canceled by the user, or time limit expires
For the returnURL parameter option, your iPhone app must implement URL schemes as well. Launching Your Own Application via a Custom URL Scheme provides a good description on how to implement your own custom URL scheme.