Basically I have started to get a little knocking noise on my front passenger side and my immediate thought was it could be the bushes.

Its not when i go over bumps but small crevas's in the road or grids, stuff that just vibrates the wheel.

Anyone know what it could be?

Ive got a smiliar noise but mine seems to be some sort of internal noise like something rattling. not put my finger on it yet mind.

Could be the drop links. When one of mine went, exactly the same symptoms.

Bushes are simple to check, put the car on full lock in the opposite direction of the side you want to check and lay down next to the rear of the wheel, you'll have a reasonable view of the back of the console, the bush should be vertical and straight, in my case it was obviously ripped top and bottom and sat more 20 to 11 ( > )than 6 o'clock ( | ). Drop links are as easy to replace as they are to check, the pair I had were FUBAR but the p/s didn't appear to be till I got it out, the d/s was knocking which is what made me check the bushes. Other thing to check is the ARB and ARB bushes but they're less likely.

If you do decide to replace the bushes I really would recommend Powerflex as you don't need a special tool and the whole job is a hell of a lot easier than using one, took me just over an hour including having a cuppa in between sides.