Analyzing the Page Source, RikaLeigh and AUZ505 found that the page background (which appears to be solid black) actually includes an image, which can be accessed at the following URL: http://www.eyeamhere.com/PL/noletters.png
Typing anything in the textbox on the page and clicking the "check" button will submit the text from the textbox as a URL argument, redirecting to: http://www.eyeamhere.com/index.asp?capital=whateveryoutyped
Update 5 April 2009
Hx3 detected that the button now says "cheCk"
Olorin detected that there is an additional background.gif, which when saved and opened in an image viewer reveals the following message in the right corner (image turned for easier reading):
see also Letter