What about using the RPi Camera Module? I am not sure how much power that consumes compared to your usb camera. If you do wanna check out the RPi Camera Module, then you can have a look at the documentation here to see if its something that fits your needs.
If you still are considering USB hubs, then you can see a list here with RPi-working usb hubs with power ratings.
Additional info:
Model A ratings: 300mA. Model B ratings: 700mA. (Reference-A, Reference-B)
The RPi + camera draws about 260 mA more current when recording video, than without the camera. The Model B is about 550 mA by itself, so camera use pushes it over 800 mA. (Reference)
Nearly 300 mA for the camera module alone (Reference)
To save ~2-20 mA on the RPi Camera Module, you can turn off the red led (Reference)
If you want a simple way of measuring how much power a USB device is using, you can buy THIS device with free shipping. (5,99USD)
A computer's usb port can supply up to 500 mA, unless you have got USB 3.0 which can supply 900mA (Reference)