Thanks Liz,
Not 100% what I was after but has put me onto "ON DUPLICATE KEY UPDATE".
Now I just need to decide if I should update my MySQL :)
Cheers,
Reagen

Update: My reasons for not using REPLACE is from my understanding it will delete the row and re-insert it with any column that I dont specify a value for, becoming the default value. I am after something where I am able to just update one column value keeping the others in there also.