Steering Wheel Vibration

Just a quick question - on the motorway I seem to be getting intermittent light steering vibration/wobble - nothing major or that makes the car pull to the left - thought it was down to the different road surfaces but I cant figure it out - one minute it will do it, the next not - anything I can check?

Cheers
 
have a look to see if any of the balance weights have come off the wheel

also check to make sure the wheel hasnt been flat spotted (check on inside of wheel rim)
 
i had the same problem and after having my tyres changed and wheels re balanced all is fine so i think a weight may have fallen off
 
Cheers for replies lads - due to get my wheels refurbed anyways so will get them balanced and tracking checked.