Visiting wowreputationcalculator.com prompts you to enter your name, server, and whether it's a US or EU server. I presume it then reads your reputation information from the Armory and then processes it in a plain but functional way that shows you how many turn-ins and/or quests you need to reach the next level with most of the key Burning Crusade factions. Let me tell you, I'm bookmarking this puppy right now, even if I'm a little disappointed to suddenly realize how long it's going to take me to get exalted with the Kurenai.
This is a very handy tool for reputation grinding. I've seen some add-ons in the past that will count quest items for you, but this is a really excellent resource. Thanks to Grumbles for making it happen for the US players!