The only cameras that will work well in bars, clubs, etc are DSLR (Digital Single Lens Reflex) cameras.

Such a camera would cost a minimum of about $700 and are neither slim nor pocket sized.

Fujifilm makes small cameras that give the best performance in low light situations:

The are not as good as a DSLR camera but perform better than the other small cameras in low light.

The point and shoot Fujifilm F20 will be your best choice.