I've been to 8 (yes, 8) weddings in the last few months and most of them had set up an on-line present ordering system with for example, Debenhams or JLewis. They then delivered the presents.
However, we always took a card with us and there was always a card table where some people had placed small presents (those that chose not to go off the list). We bought them down at the beginning of the evening reception. That seemed pretty much the 'done' thing at the 'done' time but every wedding's different I guess!!! Good luck