Is there an equivalent to
console.time(\'\'); console.timeEnd(\'\');
in IE8 Developer Tools?
If you want to use Firebug in IE, there is a version called Firebug Lite, which can be used in any browser as a 'Bookmarklet'.
http://getfirebug.com/firebuglite
It isn't as functional as the real thing, but it can do a lot so it may be worth a try.