I generally don't see many people post incidents of good service but I think this company deserves a shout.
I have just received the much needed 0BA brass grub screws I ordered at around 15:00 yesterday in the post this morning from www.ba-bolts.co.uk.
They are mostly geared to the model engineering community but the have a large selection of the small stuff in steel or brass.
You can buy your tiny screw requirements singly or in quantity, not need to buy a bag of ten just to get two!
Probably the quickest service I have ever had and will be getting my custom again.