[danielrw7]

This bit is great:

  box = box.replace(/#/g, function() { 
  	i++
  	if (str[i]) { 
  		return str[i] 
  	} else { 
  		return "";
  	}
  });

It would be cool if you could select which characters (or all characters except for space) will be replaced with the data URI.

[yorwba]

Just replace that /#/g with /[^\s]/g to replace all non-whitespace characters.

[aehtyb]

be forewarned that the reason it's asking you to use only #'s and spaces is the effect only works if the ascii image is very contrast-y. if the ascii art makes use of gradients (....:::;;;iiii@@@@) the effect won't be as obvious or work at all.

[skeoh]

Does [^\s] match anything \S doesn't?