If you use jquery, I wrote this really simple snippet that I use for quick down and dirty debugging.
var logit = function(x){$('body').append('<div id=logit></div>');$('#logit').css({'background':'#000','position':'fixed','bottom':0,'right':0,'color':'#fff','padding':5,'font-family':'arial','font-size':'9px','z-index':9999});$('#logit').append(x+'<br>');};
It could very easily be adjusted for non-jquery too.
Then just call it like: logit(whateverYouWantToDisplay);
var logit = function(x){$('body').append('<div id=logit></div>');$('#logit').css({'background':'#000','position':'fixed','bottom':0,'right':0,'color':'#fff','padding':5,'font-family':'arial','font-size':'9px','z-index':9999});$('#logit').append(x+'<br>');};
It could very easily be adjusted for non-jquery too.
Then just call it like: logit(whateverYouWantToDisplay);