Justgiving is a cheap and easy way to make a donation online and especially useful if you are organising a fundraising event for NASS or taking part in a sponsored event. 

You can create your own fundraising page about any event you are organising or taking part in and people can sponsor you by making payments via the justgiving site. This takes away the need for paper forms and the worry about collecting cheques and cash. Justgiving  even collects giftaid.

Just go to justgiving and put NASS in the search a charity section.