Some companies use DDs. They say they are better than SOs because you are informed if the payment stops, and also you can put up your prices by just informing the customer and then changing the DD yourself.
the downside is they are more expensive than standing orders, and you have to pay a setup fee which is around £2.50 i think, but you have to pay that again if the customer cancels the DD for some reason (they'll do this sometimes).
we use SOs ourselves currently and they work well, unless the customer stops paying you, if the SO doesnt work first time also you are waiting for the customer to let you know (which they dont always), and also putting up your prices is a reaql hassle as you are waiting for the customer to get around to doing it, which can take a while.