Thanks for the comments guys.
Naith - the Sigma is a great lens and in good light gives some quality results. I got mine from Mifsuds in Brixham, Devon for £153
here
It's the APO version with the built-in auto-focus motor.
The "macro" capability is the next best thing to a dedicated macro lens and by flicking the switch to macro you decrease the minimum focal distance from 1.5m to 0.95m meaning you can get closer to the subject...along with cropping after you can get some great photos. Good bokeh too with this lens for more creative shots.