Like Twitter, charity: water was pretty much unknown to me six months ago. But like Twitter, charity: water, while somewhat baffling, is ignored at charities' peril. charity: water (yes – that is a purposeful and pretentious lack of capital letters despite the fact that it is clearly a proper noun) is only three years old but in its short life has come to set the standard for fundraising from social networks.

Well, I thoroughly enjoyed my first live London Marathon and our PF flickr site has the photos to prove it. And I am delighted to hear today that a record amount has been raised for charity. On the JustGiving donation site alone 17,843 runners raised £18,055,555.37. Including gift aid their fundraising total is £22,459,155.11 - a 7 per cent increase on last year.

Just a quick message to all the professional fundraisers taking part in Sunday's London Marathon who are running the race.

Many argue for the removal, or replacement, of 'donate now' buttons on charity websites. But a recent usability study of such sites shows that many users find it hard to donate. So who's right?