Stuart, round here you can pick em up off the tow path of the canal......
Sorry about that (true though), they are available from a good many outlets mate, but be carfull when using a syringe to inject air, keep the needle well away from your own flesh, cos an air bubble in the blood stream is a killer!!!
Hope I'm not getting you to suck eggs and all that, Keep the needles in their covers when not in use, and don't put the worm on yer leg(or other) whilst you try to get the needle in..............Like I once did...not good news.