Yes, Dusty Bin, there are things that you can buy, in DIY stores or hardware stores, little platsic pads or green felt type of pads, alternativey i guess you could always buy a square of felt and cut them to the right shape size and glue them?
We've had fitted just the things you need - they are available from B&Q kitchen department and are screwed to the side of the casing at the unhinged side of the door - I have thrown the bag out that contained them but I will describe them for you -
They are 5 - 6cm in length rectangular shaped and can be best described as a soft closing plunger which will not allow the door to slam shut.
Not very expensive about �20 for 15 if I remember correct - ours were fitted by the tradesman who fitted our kitchen so I couldn't advise on what size the holes for the screws (they are short/fat screws) needed to be but I'm sure the "expert" at the kitchen dept. will be able to tell you.