Here is a list of all the best online weight loss tools I have found.

Calorie/Exercise Journal Sites:
Sparkpeople - Also has videos of exercises and a community focus
Fitday
Nutridiary

BMI, RMR, BMR, ideal heart rate, ideal weight, etc. Caculators:
Libraryspot

Pictures/Clips of Muscle Groups & Exercises:
Exrx

Calories Burned Calculator:
Caloriesperhour

Weight Loss Ticker/Tracker (image charting progress):
Tickerfactory
3fatchicks

Sweet Calorie Counter - No signing up or downloading anything!